TY - JOUR TI - Relating reorganization energies, exciton diffusion length and non-radiative recombination to the room temperature UV-vis absorption spectra of NF-SMA AU - Kashani, Somayeh AU - Wang, Zhen AU - Risko, Chad AU - Ade, Harald T2 - MATERIALS HORIZONS AB - Multiparameter Franck–Condon analyses of absorption spectra of Y6 in dilute solutions reveals that Y6 exhibits a high conformation uniformity and the smallest intra-molecular reorganization energy among the materials studied. DA - 2022/12/9/ PY - 2022/12/9/ DO - 10.1039/d2mh01228f VL - 12 SP - SN - 2051-6355 ER - TY - JOUR TI - Suppressed recombination loss in organic photovoltaics adopting a planar-mixed heterojunction architecture AU - Jiang, Kui AU - Zhang, Jie AU - Zhong, Cheng AU - Lin, Francis R. AU - Qi, Feng AU - Li, Qian AU - Peng, Zhengxing AU - Kaminsky, Werner AU - Jang, Sei-Hum AU - Yu, Jianwei AU - Deng, Xiang AU - Hu, Huawei AU - Shen, Dong AU - Gao, Feng AU - Ade, Harald AU - Xiao, Min AU - Zhang, Chunfeng AU - Jen, Alex K-Y T2 - NATURE ENERGY DA - 2022/11// PY - 2022/11// DO - 10.1038/s41560-022-01138-y VL - 7 IS - 11 SP - 1076-1086 SN - 2058-7546 ER - TY - JOUR TI - Insights into the Local Bulk-Heterojunction Packing Interactions and Donor-Acceptor Energy Level Offsets in Scalable Photovoltaic Polymers AU - Jones, Austin L. AU - Ho, Carr Hoi Yi AU - Schneider, Sebastian A. AU - Zhang, Junxiang AU - Pei, Yusen AU - Wang, Jiayu AU - Zhan, Xiaowei AU - Marder, Seth R. AU - Toney, Michael F. AU - So, Franky AU - Reddy, G. N. Manjunatha AU - Reynolds, John R. T2 - CHEMISTRY OF MATERIALS AB - An energy level offset in organic solar cells (OSCs) is necessary for efficient charge generation and separation. To date, there are several polymer donor–non-fullerene acceptor (NFA) bulk-heterojunction (BHJ) systems with a negligible ionization energy (IE) level offset achieving high power conversion efficiencies (PCEs) over 15%. Although these donor–acceptor pairs perform well in solar cells, there is little understanding on why some systems can achieve this phenomenon, and therefore, many of these BHJs are discovered through a trial-and-error process. Here, we investigate how OSC efficiencies can be modulated by adjusting the IE level offset in a series of PTQ10 n:m random terpolymer donors by means of solar cell performance (open circuit voltage (VOC) and short-circuit current (JSC)) when paired with Y6 and IDIC acceptors. PTQ10’s IE level was adjusted through a copolymerization of thiophene (n), bithiophene (m), and quinoxaline monomer units in different ratios, whereby 10% bithiophene leads to a 0.05 eV decrease in the polymer’s IE. The incorporation of 10% bithiophene (PTQ10 90:10) led to a 1.3 ± 0.5 mA/cm2 increase in JSC when paired with Y6 (PCE = 13.8 ± 0.4%) in conjunction with an incremental decrease in VOC and fill factor (FF) when compared to PTQ10 (PCE = 14.7 ± 0.1%). Increasing the bithiophene content to 20% (PTQ10 80:20) exacerbated the decrease in VOC and FF further without the benefit of increased JSC. The drop in FF with increasing bithiophene incorporation correlated with increasing edge-on orientation in the neat polymer and polymer:Y6 BHJ blend films, shown by grazing-incidence wide-angle X-ray scattering measurements. High-field solid-state (ss)NMR spectroscopy analysis of single component PTQ10, Y6, and PTQ10:Y6 BHJ blends provides a complementary insight into how a low IE level offset system (PTQ10:Y6) imparts high performance. By resolving inter- and intramolecular packing interactions at sub-nanometer distances, ssNMR results offer key insights into the changes in local structures and conformations in the vicinity of the alkoxy PTQ10 side chains and in the Y6 end group in BHJ blends when compared to the neat compounds. Despite the changes in local structures, the BHJ morphology maintains pure D-A domains and preserves the microstructure, which correlates with the high-performing solar cells. A synergic combination of chemical design, multiscale morphology characterization, and device physics shown in this study provides an excellent strategy to investigate the BHJ and its role in organic solar cell performance. DA - 2022/7/27/ PY - 2022/7/27/ DO - 10.1021/acs.chemmater.2c01121 VL - 7 SP - SN - 1520-5002 ER - TY - JOUR TI - Small-Molecule Acceptor with Unsymmetric Substituents and Fused Rings for High-Performance Organic Solar Cells with Enhanced Mobility and Reduced Energy Losses AU - Li, Zechen AU - Kong, Xiaolei AU - Chen, Zeng AU - Angunawela, Indunil AU - Zhu, Haiming AU - Li, Xiaojun AU - Meng, Lei AU - Ade, Harald AU - Li, Yongfang T2 - ACS APPLIED MATERIALS & INTERFACES AB - A new unsymmetric small-molecule acceptor (SMA) BTPOSe-4F was designed by unsymmetric structure modification to Y6 with an alkyl upper side chain replaced by an alkoxy side chain and a sulfur atom in its central fused ring replaced by a selenium atom, for the application as an acceptor to fabricate organic solar cells (OSCs). BTPOSe-4F exhibits a higher lowest unoccupied molecular orbital (LUMO) energy level, a reduced nonradiation energy loss, and better charge extraction properties in its binary OSCs with a higher Voc of 0.886. Furthermore, the ternary OSCs with the addition of PC71BM demonstrated a higher power conversion efficiency (PCE) of 17.33% with Voc of 0.890 V. This work reveals that the unsymmetric modification strategy can further give impetus to the photovoltaic performance promotion of OSCs for Y6-series SMAs. DA - 2022/11/9/ PY - 2022/11/9/ DO - 10.1021/acsami.2c17235 VL - 11 SP - SN - 1944-8252 KW - organic solar cells KW - unsymmetric molecular structure KW - alkoxy substituent KW - small-molecule acceptors KW - nonradiative energy loss ER - TY - JOUR TI - Importance of Electric-Field-Independent Mobilities in Thick-Film Organic Solar Cells AU - Ho, Carr Hoi Yi AU - Pei, Yusen AU - Qin, Yunpeng AU - Zhang, Chujun AU - Peng, Zhengxing AU - Angunawela, Indunil AU - Jones, Austin L. AU - Yin, Hang AU - Iqbal, Hamna F. AU - Reynolds, John R. AU - Gundogdu, Kenan AU - Ade, Harald AU - So, Shu Kong AU - So, Franky T2 - ACS APPLIED MATERIALS & INTERFACES AB - In organic solar cells (OSCs), a thick active layer usually yields a higher photocurrent with broader optical absorption than a thin active layer. In fact, a ∼300 nm thick active layer is more compatible with large-area processing methods and theoretically should be a better spot for efficiency optimization. However, the bottleneck of developing high-efficiency thick-film OSCs is the loss in fill factor (FF). The origin of the FF loss is not clearly understood, and there a direct method to identify photoactive materials for high-efficiency thick-film OSCs is lacking. Here, we demonstrate that the mobility field-dependent coefficient is an important parameter directly determining the FF loss in thick-film OSCs. Simulation results based on the drift–diffusion model reveal that a mobility field-dependent coefficient smaller than 10–3 (V/cm)−1/2 is required to maintain a good FF in thick-film devices. To confirm our simulation results, we studied the performance of two ternary bulk heterojunction (BHJ) blends, PTQ10:N3:PC71BM and PM6:N3:PC71BM. We found that the PTQ10 blend film has weaker field-dependent mobilities, giving rise to a more balanced electron–hole transport at low fields. While both the PM6 blend and PTQ10 blend yield good performance in thin-film devices (∼100 nm), only the PTQ10 blend can retain a FF = 74% with an active layer thickness of up to 300 nm. Combining the benefits of a higher JSC in thick-film devices, we achieved a PCE of 16.8% in a 300 nm thick PTQ10:N3:PC71BM OSC. Such a high FF in the thick-film PTQ10 blend is also consistent with the observation of lower charge recombination from light-intensity-dependent measurements and lower energetic disorder observed in photothermal deflection spectroscopy. DA - 2022/10/11/ PY - 2022/10/11/ DO - 10.1021/acsami.2c11265 VL - 10 SP - SN - 1944-8252 KW - organic photovoltaic KW - fill factor KW - thick film KW - mobility KW - field dependence KW - electric field ER - TY - JOUR TI - Cavity Engineering of Perovskite Distributed Feedback Lasers AU - Dong, Qi AU - Fu, Xiangyu AU - Seyitliyev, Dovletgeldi AU - Darabi, Kasra AU - Mendes, Juliana AU - Lei, Lei AU - Chen, Yi-An AU - Chang, Chih-Hao AU - Amassian, Aram AU - Gundogdu, Kenan AU - So, Franky T2 - ACS PHOTONICS DA - 2022/8/18/ PY - 2022/8/18/ DO - 10.1021/acsphotonics.2c00917 VL - 8 SP - SN - 2330-4022 KW - perovskite lasers KW - distributed feedback lasers KW - cavity fabrication KW - cavity engineering ER - TY - JOUR TI - Revealing aggregation of non-fullerene acceptors in intermixed phase by ultraviolet-visible absorption spectroscopy AU - Fang, Jin AU - Wang, Zhen AU - Chen, Yiyao AU - Zhang, Qing AU - Zhang, Jianqi AU - Zhu, Lingyun AU - Zhang, Maojie AU - Cui, Zheng AU - Wei, Zhixiang AU - Ade, Harald AU - Ma, Chang-Qi T2 - CELL REPORTS PHYSICAL SCIENCE AB - Non-fullerene acceptor (NFA) aggregation is crucial in determining bulk-heterojunction (BHJ) organic photovoltaic (OPV) performance. However, it is still a big challenge to characterize the nanostructure of NFAs in the disordered donor-acceptor intermixed phase. Here, we demonstrate a method to characterize NFA aggregation and composition in the intermixed phase by measuring NFA concentration-dependent ultraviolet-visible (UV-vis) absorption spectroscopy of BHJ films. In various polymer:NFA films, an absorption shift as a function of increasing molecular concentration (ASIMC) phenomenon is observed, and different NFA aggregation behaviors can be distinguished. The ASIMC method was then applied to study the influence of processing conditions on the NFA concentration in the intermixed phase of devices to establish a correlation with device efficiency. The current work provides a feasible tool to study the nanostructure of NFAs in the complex polymer matrix and to understand the variations in the NFA concentration in the intermixed phase under non-equilibrium conditions. DA - 2022/7/20/ PY - 2022/7/20/ DO - 10.1016/j.xcrp.2022.100983 VL - 3 IS - 7 SP - SN - 2666-3864 ER - TY - JOUR TI - Solid additive tuning of polymer blend morphology enables non-halogenated-solvent all-polymer solar cells with an efficiency of over 17% AU - Hu, Ke AU - Zhu, Can AU - Ding, Kan AU - Qin, Shucheng AU - Lai, Wenbin AU - Du, Jiaqi AU - Zhang, Jianqi AU - Wei, Zhixiang AU - Li, Xiaojun AU - Zhang, Zhanjun AU - Meng, Lei AU - Ade, Harald AU - Li, Yongfang T2 - ENERGY & ENVIRONMENTAL SCIENCE AB - The treatment of toluene solvent and DTT additive enables the PBQ6:PYF-T- o -based all-PSC devices with PCE up to 17.06%, which is one of the highest value in non-halogenated-processed all-PSCs to date. DA - 2022/8/12/ PY - 2022/8/12/ DO - 10.1039/d2ee01727j VL - 8 SP - SN - 1754-5706 ER - TY - JOUR TI - Achieving 19% Power Conversion Efficiency in Planar-Mixed Heterojunction Organic Solar Cells Using a Pseudosymmetric Electron Acceptor AU - Gao, Wei AU - Qi, Feng AU - Peng, Zhengxing AU - Lin, Francis R. AU - Jiang, Kui AU - Zhong, Cheng AU - Kaminsky, Werner AU - Guan, Zhiqiang AU - Lee, Chun-Sing AU - Marks, Tobin J. AU - Ade, Harald AU - Jen, Alex K-Y T2 - ADVANCED MATERIALS AB - A record power conversion efficiency (PCE) of over 19% is realized in planar-mixed heterojunction (PMHJ) organic solar cells (OSCs) by adopting the asymmetric selenium substitution strategy in making a pseudosymmetric electron acceptor, BS3TSe-4F. The combined molecular asymmetry with more polarizable selenium substitution increases the dielectric constant of the D18/BS3TSe-4F blend, helping lower the exciton binding energy. On the other hand, dimer packing in BS3TSe-4F is facilitated to enable free charge generation, helping more efficient exciton dissociation and lowering the radiative recombination loss (ΔE2 ) of OSCs. As a result, PMHJ OSCs based on D18/BS3TSe-4F achieve a PCE of 18.48%. By incorporating another mid-bandgap acceptor Y6-O into D18/BS3TSe-4F to form a ternary PMHJ, a higher open-circuit voltage (VOC ) can be achieved to realize an impressive PCE of 19.03%. The findings of using pseudosymmetric electron acceptors in enhancing device efficiency provides an effective way to develop highly efficient acceptor materials for OSCs. DA - 2022/7/11/ PY - 2022/7/11/ DO - 10.1002/adma.202202089 VL - 7 SP - SN - 1521-4095 KW - electron acceptors KW - free charge generation KW - organic solar cells KW - planar-mixed heterojunctions KW - pseudosymmetry ER - TY - JOUR TI - A Top-Down Strategy to Engineer ActiveLayer Morphology for Highly Efficient and Stable All-Polymer Solar Cells AU - Fu, Huiting AU - Peng, Zhengxing AU - Fan, Qunping AU - Lin, Francis R. AU - Qi, Feng AU - Ran, Yixin AU - Wu, Ziang AU - Fan, Baobing AU - Jiang, Kui AU - Woo, Han Young AU - Lu, Guanghao AU - Ade, Harald AU - Jen, Alex K-Y T2 - ADVANCED MATERIALS AB - Abstract A major challenge hindering the further development of all‐polymer solar cells (all‐PSCs) employing polymerized small‐molecule acceptors is the relatively low fill factor (FF) due to the difficulty in controlling the active‐layer morphology. The issues typically arise from oversized phase separation resulting from the thermodynamically unfavorable mixing between two macromolecular species, and disordered molecular orientation/packing of highly anisotropic polymer chains. Herein, a facile top‐down controlling strategy to engineer the morphology of all‐polymer blends is developed by leveraging the layer‐by‐layer (LBL) deposition. Optimal intermixing of polymer components can be achieved in the two‐step process by tuning the bottom‐layer polymer swelling during top‐layer deposition. Consequently, both the molecular orientation/packing of the bottom layer and the molecular ordering of the top layer can be optimized with a suitable top‐layer processing solvent. A favorable morphology with gradient vertical composition distribution for efficient charge transport and extraction is therefore realized, affording a high all‐PSC efficiency of 17.0% with a FF of 76.1%. The derived devices also possess excellent long‐term thermal stability and can retain >90% of their initial efficiencies after being annealed at 65 °C for 1300 h. These results validate the distinct advantages of employing an LBL processing protocol to fabricate high‐performance all‐PSCs. DA - 2022/7/15/ PY - 2022/7/15/ DO - 10.1002/adma.202202608 VL - 7 SP - SN - 1521-4095 KW - all-polymer solar cells KW - blend morphology KW - device stability KW - layer-by-layer deposition KW - power conversion efficiency ER - TY - JOUR TI - A Benzo[1,2-b:4,5-b']Difuran Based Donor Polymer Achieving High-Performance (>17%) Single-Junction Organic Solar Cells with a Fill Factor of 80.4% AU - Yi, Jicheng AU - Pan, Mingao AU - Chen, Lu AU - Chen, Yuzhong AU - Angunawela, Indunil Chathurangani AU - Luo, Siwei AU - Zhang, Ting AU - Zeng, Anping AU - Chen, Jian AU - Qi, Zhenyu AU - Yu, Han AU - Liu, Wei AU - Lai, Joshua Yuk Lin AU - Kim, Ha Kyung AU - Zhu, Xunjin AU - Ade, Harald AU - Lin, Haoran AU - Yan, He T2 - ADVANCED ENERGY MATERIALS AB - Abstract In the field of non‐fullerene organic solar cells (OSCs), most of the promising polymer donors are based on benzo[1,2‐b:4,5‐b′]dithiophene (BDT) units while benzo[1,2‐b:4,5‐b′]difuran (BDF)‐based polymers have drawn less attention since the efficiencies of BDF polymer‐based devices are generally lower than those of BDT polymer‐based ones. In this contribution, the BDT unit in a polymer donor named D18 is replaced with a BDF unit, and a new polymer named D18‐Fu is synthesized. As a highly‐crystalline molecule named Y6‐1O is chosen as the acceptor, the efficiency of binary devices based on D18‐Fu can reach 16.38%. Furthermore, when one of fullerene derivatives PC 71 BM is added, the ternary devices based on D18‐Fu achieve an efficiency of 17.07% and a high fill factor (FF) of 80.4%, both of which are the highest values among those of BDF polymer‐based devices. For comparison, D18‐based ternary devices show an inferior efficiency of 15.61% mainly due to the lower FF of 73.9%. Subsequent characterization reveals that D18‐Fu possesses a more coplanar molecular geometry, leading to better morphology and higher charge mobility for a promising FF. The high performance shown in this work demonstrates the potential role of BDF units in the design of polymer donors for highly efficient OSCs. DA - 2022/7/19/ PY - 2022/7/19/ DO - 10.1002/aenm.202201850 VL - 7 SP - SN - 1614-6840 KW - benzo[1,2-b:4,5-b']difuran KW - fill factors KW - morphology KW - organic solar cells KW - polymer donors ER - TY - JOUR TI - Enhanced Surface Passivation of Lead Sulfide Quantum Dots for Short-Wavelength Photodetectors AU - Yin, Shichen AU - Ho, Carr Hoi Yi AU - Ding, Shuo AU - Fu, Xiangyu AU - Zhu, Liping AU - Gullett, Julian AU - Dong, Chen AU - So, Franky T2 - CHEMISTRY OF MATERIALS AB - Lead sulfide (PbS) quantum dots are promising solution-processed materials for short-wave infrared (SWIR) photodetectors due to their tunable band gap and solution processability. Phase-transfer ligand exchange is a common method to prepare quantum dot (QD) inks used in device fabrication. For large-sized PbS QDs used for SWIR detection, the conventional phase-transfer ligand exchange has been problematic due to the densely packed organic ligands and charge-neutral (100) facets. Here, we report a new strategy to carry out the efficient phase-transfer ligand exchange in large-sized QDs. Specifically, using lead acetate trihydrate (PbAc2·3H2O) as a precursor and methylammonium acetate (MAAc) as an additive in the ligand solution, we can facilitate the efficient phase-transfer ligand exchange and epitaxial growth of perovskite intermediate (MAPbI3–xAcx) on the (100) facets, resulting in a significant improvement in film quality suitable for device fabrication. The resulting photodiodes show a 2.5× enhancement in external quantum efficiency (EQE) compared to devices using QD inks obtained using the conventional method. Considering the low transmittance of the ITO electrode in the SWIR regime, our devices exhibit an internal quantum efficiency of over 90%. DA - 2022/6/28/ PY - 2022/6/28/ DO - 10.1021/acs.chemmater.2c00293 VL - 34 IS - 12 SP - 5433-5442 SN - 1520-5002 ER - TY - JOUR TI - Silver Nanowire Composite Electrode Enabling Highly Flexible, Robust Organic Photovoltaics AU - Booth, Ronald E. AU - Schrickx, Harry M. AU - Hanby, Georgia AU - Liu, Yuxuan AU - Qin, Yunpeng AU - Ade, Harald AU - Zhu, Yong AU - Brendan T. O'Connor, T2 - SOLAR RRL AB - Using Ag nanowires (NWs) is a promising approach to make flexible and transparent conducting electrodes for organic photovoltaics (OPVs). However, the roughness of the NWs can decrease device performance. Herein, a Ag NW electrode embedded in a UV‐curable epoxy that uses a simple mechanical lift‐off process resulting in highly planar electrodes is demonstrated. A bimodal blend of Ag NWs with varying aspect ratios is used to optimize the transparency and conductivity of the electrode. In addition, a ZnO layer is coated on the Ag NWs prior to the embedding process to ensure low contact resistance in the OPV cells. The resulting resin‐embedded ZnO‐encapsulated silver nanowire (REZEN) electrode is found to have excellent mechanical stability. REZEN electrode‐based OPV cells exhibit comparable performance with reference devices, achieving maximum power conversion efficiency (PCE) of 13.5% and 13.6% respectively. The REZEN‐based OPV cells are also mechanically robust, retaining 97% of their PCE after 5000 cycles at R = 1.2 mm and 94% PCE after 1000 cycles at R = 0.55 mm. This flexibility is among the highest reported for freestanding devices. Thus, the REZEN electrode is a promising and simple strategy to achieve mechanically robust ITO‐free flexible OPV cells. DA - 2022/6/15/ PY - 2022/6/15/ DO - 10.1002/solr.202200264 VL - 6 SP - SN - 2367-198X KW - flexible organic photovoltaics KW - flexible transparent electrodes KW - mechanically stable organic photovoltaics KW - organic solar cells KW - silver nanowire electrodes ER - TY - JOUR TI - Optimizing spectral and morphological match of nonfullerene acceptors toward efficient indoor organic photovoltaics with enhanced light source adaptability AU - Luo, Siwei AU - Bai, Fujin AU - Zhang, Jianquan AU - Zhao, Heng AU - Angunawela, Indunil AU - Zou, Xinhui AU - Li, Xiaojun AU - Luo, Zhenghui AU - Feng, Kui AU - Yu, Han AU - Wong, Kam Sing AU - Ade, Harald AU - Ma, Wei AU - Yan, He T2 - NANO ENERGY AB - High-performance indoor organic photovoltaics (IOPV) require large-bandgap material systems to absorb visible light efficiently and reduce energy loss. However, state-of-the-art non-fullerene acceptors (NFAs) have absorptions in the near-infrared region and are thus not suitable for IOPV applications. Herein, we report a series of large-bandgap (>1.70 eV) NFAs named FCC-Cl-C8, FCC-Cl-4Ph and FCC-Cl-6Ph by modifying the alkyl side chains with alkylphenyl chains partially or completely. Results show that the bulky alkylphenyl side chains can finely tune the absorption properties of the NFAs and also affect their morphological properties. Interestingly, the best-performing NFA is the one (named FCC-Cl-4Ph) with partial alkyl and alkylphenyl substitutions, which blue-shift the absorption of the NFAs while minimizing the negative morphological effect of the bulky alkylphenyl chains. As a result, FCC-Cl-4Ph can achieve excellent indoor efficiencies over 29% under a 3000 K LED lamp at 1000 lux and show better solution processability over FCC-Cl-C8. More importantly, FCC-Cl-4Ph can maintain high indoor performance (29.7–26.8% at 1000 lux) under a wide range of indoor lighting spectra (2600, 3000, 4000, and 6500 K LED lamps), which should be due to the blue-shifted spectra of FCC-Cl-4Ph and better matching with various indoor conditions. This work reveals an interesting structure-property relationship and offers useful strategies for the further design of NFAs toward efficient IOPV devices. DA - 2022/7// PY - 2022/7// DO - 10.1016/j.nanoen.2022.107281 VL - 98 SP - SN - 2211-3282 KW - Organic solar cells KW - Indoor organic photovoltaics KW - Non-fullerene acceptors KW - Side-chain engineering ER - TY - JOUR TI - 16.52% Efficiency All-Polymer Solar Cells with High Tolerance of the Photoactive Layer Thickness AU - Zhang, Wenqing AU - Sun, Chenkai AU - Angunawela, Indunil AU - Meng, Lei AU - Qin, Shucheng AU - Zhou, Liuyang AU - Li, Shaman AU - Zhuo, Hongmei AU - Yang, Guang AU - Zhang, Zhi-Guo AU - Ade, Harald AU - Li, Yongfang T2 - ADVANCED MATERIALS AB - All-polymer solar cells (all-PSCs) have drawn growing attention and achieved tremendous progress recently, but their power conversion efficiency (PCE) still lags behind small-molecule-acceptor (SMA)-based PSCs due to the relative difficulty on morphology control of polymer photoactive blends. Here, low-cost PTQ10 is introduced as a second polymer donor (a third component) into the PM6:PY-IT blend to finely tune the energy-level matching and microscopic morphology of the polymer blend photoactive layer. The addition of PTQ10 decreases the π-π stacking distance, and increases the π-π stacking coherence length and the ordered face-on molecular packing orientation, which improves the charge separation and transport in the photoactive layer. Moreover, the deeper highest occupied molecular orbital energy level of the PTQ10 polymer donor than PM6 leads to higher open-circuit voltage of the ternary all-PSCs. As a result, a PCE of 16.52% is achieved for ternary all-PSCs, which is one of the highest PCEs for all-PSCs. In addition, the ternary devices exhibit a high tolerance of the photoactive layer thickness with high PCEs of 15.27% and 13.91% at photoactive layer thickness of ≈205 and ≈306 nm, respectively, which are the highest PCEs so far for all-PSCs with a thick photoactive layer. DA - 2022/4/17/ PY - 2022/4/17/ DO - 10.1002/adma.202108749 VL - 4 SP - SN - 1521-4095 KW - all-polymer solar cells KW - energy level matching KW - morphology control KW - photoactive layer thickness KW - ternary devices ER - TY - JOUR TI - Room-temperature superfluorescence in hybrid perovskites and its origins AU - Biliroglu, Melike AU - Findik, Gamze AU - Mendes, Juliana AU - Seyitliyev, Dovletgeldi AU - Lei, Lei AU - Dong, Qi AU - Mehta, Yash AU - Temnov, Vasily V. AU - So, Franky AU - Gundogdu, Kenan T2 - NATURE PHOTONICS DA - 2022/4// PY - 2022/4// DO - 10.1038/s41566-022-00974-4 VL - 16 IS - 4 SP - 324-+ SN - 1749-4893 ER - TY - JOUR TI - Organic solar powered greenhouse performance optimization and global economic opportunity AU - Ravishankar, Eshwar AU - Booth, Ronald E. AU - Hollingsworth, Joseph A. AU - Ade, Harald AU - Sederoff, Heike AU - DeCarolis, Joseph F. AU - Brendan T. O'Connor, T2 - ENERGY & ENVIRONMENTAL SCIENCE AB - This work integrates greenhouse energy demand, solar power production, and plant growth modeling to assess the economic opportunity of organic solar powered greenhouses. Results show these systems have positive economic outlook across broad climates. DA - 2022/3/10/ PY - 2022/3/10/ DO - 10.1039/D1EE03474J VL - 15 IS - 4 SP - SN - 1754-5706 UR - https://doi.org/10.1039/D1EE03474J ER - TY - JOUR TI - Low Voltage-Loss Organic Solar Cells Light the Way for Efficient Semitransparent Photovoltaics AU - Luginbuhl, Benjamin R. AU - Ko, Seo-Jin AU - Ran, Niva A. AU - Hu, Huawei AU - Becwar, Shona M. AU - Karki, Akchheta AU - Seifrid, Martin AU - Okubo, Takashi AU - Wang, Ming AU - Ade, Harald W. AU - Chmelka, Bradley F. AU - Bazan, Guillermo C. AU - Reddy, G. N. Manjunatha AU - Nguyen, Thuc-Quyen T2 - SOLAR RRL AB - Organic solar cells that are transparent to visible light are highly desirable for applications such as window treatments or solar greenhouse panels. A key challenge is to simultaneously transmit most photons between 400 and 700 nm while retaining a high short‐circuit current and power conversion efficiency (PCE). Here, organic bulk heterojunction (BHJ) solar cells consisting of a donor polymer (PM2) is reported and the non‐fullerene acceptor ITIC‐Th achieves a PCE of 9.3%, and the BHJ thin films exhibit an average visible transmittance over 40%. This value is achieved primarily due to a very high open‐circuit voltage ( V OC ) of 0.93 V, which represents a voltage loss of only 0.50 V relative to the material optical bandgap, E opt . In PM2:PC 61 BM devices, this voltage loss increases to 0.62 V ( V OC = 0.82 V). It is found that this difference in V OC is due to higher nonradiative recombination in the fullerene‐based solar cell, suggesting that non‐fullerene acceptors may lead to better performance in semi‐transparent devices. The optoelectronic properties associated with PM2:ITIC‐Th and PM2:PC 61 BM blends are further corroborated by different morphological features and local structures at the donor‐acceptor interfaces characterized by atomic force microscopy, X‐ray scattering, and solid‐state NMR spectroscopy techniques. DA - 2022/3/16/ PY - 2022/3/16/ DO - 10.1002/solr.202200135 VL - 3 SP - SN - 2367-198X UR - https://doi.org/10.1002/solr.202200135 KW - non-fullerene acceptors KW - non-fullerene organic solar cells KW - organic solar cells KW - recombination KW - semitransparent solar cells KW - solid-state NMR KW - voltage losses ER - TY - JOUR TI - Beyond energy balance in agrivoltaic food production: Emergent crop traits from wavelength-selective solar cells AU - Charles, Melodi AU - Edwards, Brianne AU - Ravishankar, Eshwar AU - Calero, John AU - Henry, Reece AU - Rech, Jeromy AU - Saravitz, Carole AU - You, Wei AU - Ade, Harald AU - Brendan, O’Connor AU - Sederoff, Heike AB - Semi-transparent organic solar cells (ST-OSCs) offer new agrivoltaic opportunities to meet the growing demands for sustainable food production. The tailored absorption/transmission spectrum of ST-OSCs not only impacts the power generated, but also aspects of crop growth, development and responses to the biotic and abiotic environments. The general relationships between these variables are unknown. Here, we grow red oak leaf lettuce ( Lactuca sativa ), a traditional greenhouse crop, under three different ST-OSC filters and observe little overall differences on productivity in response to the altered light exposure. In contrast, several key traits involving nutrient content and nitrogen utilization as well as plant defense against herbivory and pathogens are modified over the controls under select OSCs. Overall, our genomic analysis reveals that lettuce production exhibits beneficial traits under exposure from select ST-OSCs. ST-OSCs integrated into greenhouses are, therefore, not only a promising technology for energy-neutral crop production as previously shown but can deliver benefits beyond those based on energy-balance considerations. DA - 2022/3/13/ PY - 2022/3/13/ DO - 10.1101/2022.03.10.482833 UR - https://doi.org/10.1101/2022.03.10.482833 ER - TY - JOUR TI - Curved Mirror Arrays for Light Extraction in Top-Emitting Organic Light-Emitting Diodes AU - Amoah, Stephen AU - Fu, Xiangyu AU - Yin, Shichen AU - Dong, Qi AU - Dong, Chen AU - So, Franky T2 - ACS APPLIED MATERIALS & INTERFACES AB - The light outcoupling efficiency of a top-emitting organic light-emitting diode (OLED) is only about 20%, and the majority of the light is trapped in the waveguide modes and surface plasmon polariton (SPP) modes. Extracting the trapped modes can reduce the device power consumption and improve the operating lifetime. In this study, we demonstrate a top-emitting OLED structure with a dielectric spacer to suppress the SPP mode and with a patterned back mirror to extract the waveguide modes. We examine and compare several curved mirror arrays and conclude that a micromirror array (μMA) can efficiently extract the waveguide modes while minimizing the absorption loss. The optimized μMA device with a semi-transparent top electrode shows a 36% external quantum efficiency, 2 times higher than the referenced device. This optical design can be easily incorporated into a top-emitting device and has a great potential for displays and lighting applications. DA - 2022/2/15/ PY - 2022/2/15/ DO - 10.1021/acsami.1c21128 VL - 2 SP - 9377-9385 SN - 1944-8252 KW - OLED KW - top-emitting KW - light extraction KW - embedded scattering layer KW - waveguide mode KW - SPP mode ER - TY - JOUR TI - Ultrathin P(NDI2OD-T2) Films with High Electron Mobility in Both Bottom-Gate and Top-Gate Transistors AU - Steckmann, Thomas AU - Angunawela, Indunil AU - Kashani, Somayeh AU - Zhu, Youqin AU - Nahid, Masrur M. AU - Ade, Harald AU - Gadisa, Abay T2 - ADVANCED ELECTRONIC MATERIALS AB - Abstract Ultrathin organic films (typically < 10 nm) attracted great attention due to their (semi)transparency and unique optoelectronic properties that benefit applications such as sensors and flexible electronics. At the core of that, achieving high mobility in an ultrathin film is essential for the efficient operation of relevant electronic devices. While the state‐of‐the‐art material systems, e.g., P(NDI2OD‐T2) also known as N2200 can achieve high mobility in a thin film (typically > 20 nm), multitudinous challenges remain in processing an ultrathin film exhibiting desired charge transport morphology within a preferred thickness limit. Here, high electron mobility (a tenfold increase compared to annealed spin‐coated films) is reported in both the top and bottom‐gate configuration organic field‐effect transistors comprising ultrathin N2200 films produced with a water‐floating film transfer method. A range of characterization techniques are used to investigate these ultrathin films and their microstructure, and conclude that favorable edge‐on polymer orientation at the top as well as throughout the ultrathin film thickness and the quality of π–π ordering as captured by the largest coherences length resulted in this high mobility in N2200 ultrathin films, in stark contrast to the commonly observed microstructural gradient in spin‐coated thin films. The results provide new insight into the electronic and microstructural properties of thin films of organic semiconductors. DA - 2022/3/2/ PY - 2022/3/2/ DO - 10.1002/aelm.202101324 VL - 3 SP - SN - 2199-160X UR - https://doi.org/10.1002/aelm.202101324 KW - edge-on KW - mobility KW - transistor KW - ultrathin KW - water-processing ER - TY - JOUR TI - Consensus statement: Standardized reporting of power-producing luminescent solar concentrator performance AU - Yang, Chenchen AU - Atwater, Harry A. AU - Baldo, Marc A. AU - Baran, Derya AU - Barile, Christopher J. AU - Barr, Miles C. AU - Bates, Matthew AU - Bawendi, Moungi G. AU - Bergren, Matthew R. AU - Borhan, Babak AU - Brabec, Christoph J. AU - Brovelli, Sergio AU - Bulovic, Vladimi AU - Ceroni, Paola AU - Debije, Michael G. AU - Delgado-Sanchez, Jose-Maria AU - Dong, Wen-Ji AU - Duxbury, Phillip M. AU - Evans, Rachel C. AU - Forrest, Stephen R. AU - Gamelin, Daniel R. AU - Giebink, Noel C. AU - Gong, Xiao AU - Griffini, Gianmarco AU - Guo, Fei AU - Herrera, Christopher K. AU - Ho-Baillie, Anita W. Y. AU - Holmes, Russell J. AU - Hong, Sung-Kyu AU - Kirchartz, Thomas AU - Levine, Benjamin G. AU - Li, Hongbo AU - Li, Yilin AU - Liu, Dianyi AU - Loi, Maria A. AU - Luscombe, Christine K. AU - Makarov, Nikolay S. AU - Mateen, Fahad AU - Mazzaro, Raffaello AU - McDaniel, Hunter AU - McGehee, Michael D. AU - Meinardi, Francesco AU - Menendez-Velazquez, Amador AU - Min, Jie AU - Mitzi, David B. AU - Moemeni, Mehdi AU - Moon, Jun Hyuk AU - Nattestad, Andrew AU - Nazeeruddin, Mohammad K. AU - Nogueira, Ana F. AU - Paetzold, Ulrich W. AU - Patrick, David L. AU - Pucci, Andrea AU - Rand, Barry P. AU - Reichmanis, Elsa AU - Richards, Bryce S. AU - Roncali, Jean AU - Rosei, Federico AU - Schmidt, Timothy W. AU - So, Franky AU - Tu, Chang-Ching AU - Vahdani, Aria AU - Sark, Wilfried G. J. H. M. AU - Verduzco, Rafael AU - Vomiero, Alberto AU - Wong, Wallace W. H. AU - Wu, Kaifeng AU - Yip, Hin-Lap AU - Zhang, Xiaowei AU - Zhao, Haiguang AU - Lunt, Richard R. T2 - JOULE AB - Fair and meaningful device performance comparison among luminescent solar concentrator-photovoltaic (LSC-PV) reports cannot be realized without a general consensus on reporting standards in LSC-PV research. Therefore, it is imperative to adopt standardized characterization protocols for these emerging types of PV devices that are consistent with other PV devices. This commentary highlights several common limitations in LSC literature and summarizes the best practices moving forward to harmonize with standard PV reporting, considering the greater nuances present with LSC-PV. Based on these practices, a checklist of actionable items is provided to help standardize the characterization/reporting protocols and offer a set of baseline expectations for authors, reviewers, and editors. The general consensus combined with the checklist will ultimately guide LSC-PV research towards reliable and meaningful advances. DA - 2022/1/19/ PY - 2022/1/19/ DO - 10.1016/j.joule.2021.12.004 VL - 6 IS - 1 SP - 8-15 SN - 2542-4351 ER - TY - JOUR TI - Resolving the Molecular Origin of Mechanical Relaxations in Donor–Acceptor Polymer Semiconductors AU - Balar, Nrup AU - Rech, Jeromy James AU - Siddika, Salma AU - Song, Runqiao AU - Schrickx, Harry M. AU - Sheikh, Nadeem AU - Ye, Long AU - Bonilla, Anthony Megret AU - Awartani, Omar AU - Ade, Harald AU - You, Wei AU - O'Connor, Brendan T. T2 - Advanced Functional Materials AB - Abstract The thermomechanical behavior of polymer semiconductors plays an important role in the processing, morphology, and stability of organic electronic devices. However, donor–acceptor‐based copolymers exhibit complex thermal relaxation behavior that is not well understood. This study uses dynamic mechanical analysis (DMA) to probe thermal relaxations of a systematic set of polymers based around the benzodithiophene (BDT) moiety. The loss tangent curves are resolved by fitting Gaussian functions to assign and distinguish different relaxations. Three prominent transitions are observed that correspond to: i) localized relaxations driven primarily by the side chains (γ ), ii) relaxations along the polymer backbone (β ), and iii) relaxations associated with aggregates (α ). The side chains are found to play a clear role in dictating T γ , and that mixing the side chain chemistry of the monomer to include alkyl and oligo(ethylene glycol) moieties results in splitting the γ ‐relaxation. The β relaxations are shown to be associated with backbone elements along with the monomer. In addition, through processing, it is shown that the α‐relaxation is due to aggregate formation. Finally, it is demonstrated that the thermal relaxation behavior correlates well with the stress–strain behavior of the polymers, including hysteresis and permanent set in cyclically stretched films. DA - 2022/1// PY - 2022/1// DO - 10.1002/adfm.202105597 VL - 32 IS - 4 SP - 2105597 UR - https://doi.org/10.1002/adfm.202105597 KW - dynamic mechanical analysis KW - glass transition KW - mechanical stability KW - polymer semiconductors KW - thermomechanical relaxation ER -