@article{corzo_wang_gedda_yengel_khan_li_niazi_huang_kim_baran_et al._2022, title={A Universal Cosolvent Evaporation Strategy Enables Direct Printing of Perovskite Single Crystals for Optoelectronic Device Applications}, volume={34}, ISSN={0935-9648 1521-4095}, url={http://dx.doi.org/10.1002/adma.202109862}, DOI={10.1002/adma.202109862}, abstractNote={Solution-processed metal halide perovskite (MHP) single crystals (SCs) are in high demand for a growing number of printed electronic applications due to their superior optoelectronic properties compared to polycrystalline thin films. There is an urgent need to make SC fabrication facile, scalable, and compatible with the printed electronic manufacturing infrastructure. Here, a universal cosolvent evaporation (CSE) strategy is presented by which perovskite SCs and arrays are produced directly on substrates via printing and coating methods within minutes at room temperature from drying droplets. The CSE strategy successfully guides the supersaturation via controlled drying of droplets to suppress all crystallization pathways but one, and is shown to produce SCs of a wide variety of 3D, 2D, and mixed-cation/halide perovskites with consistency. This approach works with commonly used precursors and solvents, making it universal. Importantly, the SC consumes the precursor in the droplet, which enables the large-scale fabrication of SC arrays with minimal residue. Direct on-chip fabrication of 3D and 2D perovskite photodetector devices with outstanding performance is demonstrated. The approach shows that any MHP SC can now be manufactured on substrates using precision printing and scalable, high-throughput coating methods.}, number={9}, journal={Advanced Materials}, publisher={Wiley}, author={Corzo, Daniel and Wang, Tonghui and Gedda, Murali and Yengel, Emre and Khan, Jafar I and Li, Ruipeng and Niazi, Muhammad Rizwan and Huang, Zhengjie and Kim, Taesoo and Baran, Derya and et al.}, year={2022}, month={Jan}, pages={2109862} }
@article{zhang_cao_huang_danilov_chung_sun_yang_2021, title={Gamma-Ray Detection Using Bi-Poor Cs2AgBiBr6 Double Perovskite Single Crystals}, volume={9}, ISSN={["2195-1071"]}, url={https://doi.org/10.1002/adom.202001575}, DOI={10.1002/adom.202001575}, abstractNote={Abstract Lead halide perovskites have recently attracted intensive attention as competitive alternative candidates of legacy compound materials CdTe, CdZnTe, and TlBr for high sensitivity energy‐resolving gamma‐ray detection at room temperature. However, the use of lead in these lead halide perovskites, which is necessary for increasing the stopping power of gamma radiation, poses a serious environmental concern due to the high toxicity of lead. In this regard, environmental‐friendly perovskite‐based gamma‐ray detector materials with key energy‐resolving capabilities are highly desired. Here, the gamma energy‐resolving performance of a new class of all‐inorganic and lead‐free Cs 2 AgBiBr 6 double perovskite single crystals (SCs) is reported. Two types of Cs 2 AgBiBr 6 SCs, prepared by Bi‐normal and Bi‐poor precursor solutions, respectively, have been grown. Their mobilities and response to gamma radiation are presented. Density of trap states in Bi‐poor Cs 2 AgBiBr 6 SCs (2.65 × 10 9 cm −3 ) is one order of magnitude lower than that in Bi‐normal Cs 2 AgBiBr 6 SCs (3.85 × 10 10 cm −3 ). Using laser‐induced photocurrent measurements, the obtained mobility–lifetime (μ–τ) product in Bi‐poor Cs 2 AgBiBr 6 SCs is 1.47 × 10 −3 cm 2 V −1 , indicating their great potentials for gamma‐ray detection. Further, the fabricated detector based on Bi‐poor Cs 2 AgBiBr 6 SC shows response to 59.5 keV gamma‐ray with an energy resolution of 13.91%.}, number={8}, journal={ADVANCED OPTICAL MATERIALS}, publisher={Wiley}, author={Zhang, Zheng and Cao, Da and Huang, Zhengjie and Danilov, Evgeny O. and Chung, Ching-Chang and Sun, Dali and Yang, Ge}, year={2021}, month={Apr} }
@article{huang_vardeny_wang_ahmad_chanana_vetter_yang_liu_galli_amassian_et al._2021, title={Observation of spatially resolved Rashba states on the surface of CH3NH3PbBr3 single crystals}, volume={8}, ISSN={1931-9401}, url={http://dx.doi.org/10.1063/5.0053884}, DOI={10.1063/5.0053884}, abstractNote={Hybrid organic-inorganic perovskites (HOIPs) are prime candidates for studying Rashba effects due to the heavy metal and halogen atoms in their crystal structure coupled with predicted inversion symmetry breaking. Nevertheless, observation of the Rashba effect in cubic CH3NH3PbBr3 single crystals that possess bulk inversion symmetry is the subject of extensive debate due to the lack of conclusive experiments and theoretical explanations. Here, we provide experimental evidence that Rashba state in cubic CH3NH3PbBr3 single crystals at room temperature occurs exclusively on the crystal surface and depends on specific surface termination that results in local symmetry breaking. We demonstrate this using a suite of spatially resolved and depth-sensitive techniques, including circular photogalvanic effect, inverse spin Hall effect, and multiphoton microscopy, that are supported by first principle calculations. Our work suggests using surface Rashba states in these materials for spintronic applications.}, number={3}, journal={Applied Physics Reviews}, publisher={AIP Publishing}, author={Huang, Zhengjie and Vardeny, Shai R. and Wang, Tonghui and Ahmad, Zeeshan and Chanana, Ashish and Vetter, Eric and Yang, Shijia and Liu, Xiaojie and Galli, Giulia and Amassian, Aram and et al.}, year={2021}, month={Sep}, pages={031408} }
@article{zhang_chung_huang_vetter_seyitliyev_sun_gundogdu_castellano_danilov_yang_2020, title={Towards radiation detection using Cs2AgBiBr6 double perovskite single crystals}, volume={269}, ISSN={0167-577X}, url={http://dx.doi.org/10.1016/j.matlet.2020.127667}, DOI={10.1016/j.matlet.2020.127667}, abstractNote={In this work, we studied the optical- and electrical- properties of emerging Cs2AgBiBr6 double perovskite single crystals and demonstrated their potential for detecting ionizing radiation. We prepared Cs2AgBiBr6 double perovskite single crystals from a saturated aqueous solution. Low-temperature photoluminescence (PL) was employed to determine the bandgap energies of Cs2AgBiBr6, which are 2.00 eV (indirect) and 2.26 eV (direct) respectively. Using the space charge limited current method, we estimated the density of trap states and mobility of charge carriers as 1.44 × 1010 cm−3 and 7.02 cm2/V-s respectively. A lower bound value of the mobility-lifetime (μ-τ) product of 2.48 × 10−3 cm2/V was determined using 450 nm laser excitation, which was sufficient for ensuring a long drift distance of charge carriers for several radiation detector applications. Furthermore, we tested the direct response of Cs2AgBiBr6 single crystals to X-ray radiation. Our Cs2AgBiBr6 single crystal device with gold electrodes deposited on the two parallel surfaces exhibited excellent linear response to low energy X-rays.}, journal={Materials Letters}, publisher={Elsevier BV}, author={Zhang, Zheng and Chung, Ching-Chang and Huang, Zhengjie and Vetter, Eric and Seyitliyev, Dovletgeldi and Sun, Dali and Gundogdu, Kenan and Castellano, Felix N. and Danilov, Evgeny O. and Yang, Ge}, year={2020}, month={Jun}, pages={127667} }