@article{badawy_su_fadda_abdel-latif_el-shafei_elmorsy_2022, title={Highly efficient (N-benzothiazolyl)-cyanoacetamide based co-sensitizers for high efficiency dye-sensitized solar cells}, volume={249}, ISSN={["1618-1336"]}, DOI={10.1016/j.ijleo.2021.168274}, abstractNote={Four novels (N-benzothiazolyl)-cyanoacetamide-based metal-free dyes SA17–20 with D-π-A architecture were designed and synthesized as co-sensitizers for HD-2 for dye-sensitized solar cells (DSSCs). They contain strong donating moieties of trimethoxybenzene and N,N-dimethylaniline conjugated with the nitrile function of cyanoacetamide part (NHCOCH2CN) as an anchoring group. The role of donor/acceptor in the cyanoacetamide-based structure motifs of SA17–20 in the co-adsorption properties was characterized and their influence on the optical and electrochemical properties was discussed. Consistent with the experimental results, the equilibrium molecular geometries calculated using density functional theory (DFT), at the B3LYP/ 6–31 G (d, p) level, demonstrated the effect of (N-benzothiazolyl)-cyanoacetamide structures on the photovoltaic performance. Co-sensitization technique mainly depends on the uniqueness of the donor-acceptor unit of the co-sensitizer being used. Using (N-benzothiazolyl)-cyanoacetamide co-sensitizers with HD-2 showed improved power conversion efficiency (PCE) than HD-2 alone. HD-2 was used because of its high efficiency, molar extinction coefficient and photocurrent densities. While HD-2 sensitizer alone displayed PCE of (7.46%), among the co-sensitizers, SA20, containing methoxythiazole and trimethoxybenzene as a donor part attached to (CN) and (CO) as anchoring components, exhibited the best PCE of (8.27%) with Jsc (19.25 mA/cm2) and Voc (0.68 V). These results demonstrated that (N-benzothiazolyl)-cyanoacetamide dyes SA17–20 are promising candidates for efficient DSSCs.}, journal={OPTIK}, author={Badawy, Safa A. and Su, Rui and Fadda, Ahmed A. and Abdel-Latif, Ehab and El-Shafei, Ahmed and Elmorsy, Mohamed R.}, year={2022}, month={Jan} }
 @article{fang_su_hu_fu_2021, title={A simple and easy-implemented time-of-flight determination method for liquid ultrasonic flow meters based on ultrasonic signal onset detection and multiple-zero-crossing technique}, volume={168}, ISSN={["1873-412X"]}, DOI={10.1016/j.measurement.2020.108398}, abstractNote={Determination of time-of-flight (TOF) is crucially important in liquid ultrasonic flow meters. There are some deficiencies of previous TOF detection methods in practical applications. Inspired by our last work and the knowledge of clustering algorithms, we proposed a TOF determination method based on ultrasonic signal onset (USO) detection and multiple-zero-crossing technique to solve cycle-skip problem caused by waveform change. This method categorizes the ultrasonic and the noise signal, and identifies the rough position of USO. A time value from the obtained zero-crossing time values is selected as the TOF. The main advantage of the proposed method is the high insensitivity towards waveform change, i.e., the effect of amplitude characteristics change on TOF detection is negligible. Numerical experiments were done to evaluate the performance of the proposed method and its anti-noise ability. Experimental validation on a liquid ultrasonic flow meter showed the proposed method is capable of obtaining the accurate TOF.}, journal={MEASUREMENT}, author={Fang, Zehua and Su, Rui and Hu, Liang and Fu, Xin}, year={2021}, month={Jan} }
 @article{zhang_hu_su_ruan_2021, title={Design Method of Bearingless Permanent Magnet Slice Motor for Maglev Centrifugal Pump Based on Performance Metric Cluster}, url={https://www.mdpi.com/2076-0825/10/7/153}, DOI={10.3390/act10070153}, abstractNote={Different from ordinary AC machines, the design of a bearingless permanent magnet slice motor (BPMSM) considers not only the torque performance, but also the passive and active suspension properties. In addition, BPMSM for a maglev centrifugal pump has unique design characteristics due to the integration of the pump head and sensors. This paper investigates evaluation and design techniques based on a cluster of performance metrics targeting on developing BPMSM for a maglev centrifugal pump. The cluster of performance metrics for BPMSM, including passive stiffness (kz, kz/kx, kz/ky, kα, and kβ) and active factors (ki and cm), is first proposed and an evaluation function fiSi,Li is constructed. Then, practical configurations of BPMSM for a maglev centrifugal pump are summarized. Based on the cluster of performance metrics, the finite-element method (FEM) is used to explore the impact of the rotor magnetization (sinusoidal, diametric, and radial method) on motor properties. Subsequently, the complete design process of BPMSM for a maglev centrifugal pump is introduced and key differences (including three crucial geometric parameters: ratio of rotor height to diameter λ, magnetic gap length δ, and stator tooth width αst) in the design considerations between BPMSM and general bearingless motors are analyzed. Finally, the upgraded performance (kz, kα, kβ, ki, cm, and fiSi,Li increased by about 29%, 38%, 33%, 31%, 21%, and 15%, respectively) of the designed candidate is obtained, which verifies the effectiveness of the proposed design methods.}, journal={Actuators}, author={Zhang, Yifan and Hu, Liang and Su, Rui and Ruan, Xiaodong}, year={2021}, month={Jul} }
 @article{li_yu_hu_ruan_su_fu_2021, title={Modelling and Stability Analysis for a Magnetically Levitated Slice Motor (MLSM) with Gyroscopic Effect and Non-Collocated Structure Based on the Extended Inverse Nyquist Stability Criterion}, url={https://www.mdpi.com/2075-1702/9/9/201}, DOI={10.3390/machines9090201}, abstractNote={Stability of the rotor motion is the precondition for the reliable operation of magnetically levitated slice motors (MLSMs). However, with gyroscopic effect and non-collocated structure existing simultaneously, its stability analysis faces a tremendous challenge, because the torsional motions couple with the radial translational ones, making MLSM a multiple-input and multiple-output (MIMO) system with high order. Therefore, in this paper, we first establish a novel MIMO rotor dynamics closed-loop model and further convert it into an equivalent single-input and single-out (SISO) feedback control system by constructing complex variables, meanwhile reducing the system order by half. Beneficial from the equivalence between the MIMO and SISO systems, the sufficient and necessary conditions of the absolute stability of MLSM are derived by the extended inverse Nyquist stability criterion in the complex domain. Additionally, the effectiveness of the proposed modelling and stability analysis method is evaluated by simulation and experimental results. Thus, apart from PID parameters, this paper demonstrates that the stability of MLSM is also affected by the coupling of gyroscopic effect and non-collocated structure, which should serve as an essential guideline for system regulation of MLSM.}, journal={Machines}, author={Li, Lingling and Yu, Yang and Hu, Liang and Ruan, Xiaodong and Su, Rui and Fu, Xin}, year={2021}, month={Sep} }
 @article{ashraf_su_akhtar_shuja_siddiqi_el-shafei_2021, title={Molecular engineering of ruthenium-based photosensitizers with superior photovoltaic performance in DSSCs: novel N-alkyl 2-phenylindole-based ancillary ligands}, ISSN={["1369-9261"]}, DOI={10.1039/d1nj04362e}, abstractNote={In this work, we report the design and successful synthesis of two new heteroleptic polypyridyl Ru(ii) complexes (SD-5 and SD-6), by incorporating hetero-aromatic electron-donating N-alkyl-2-phenylindole moieties into the ancillary ligand.}, journal={NEW JOURNAL OF CHEMISTRY}, author={Ashraf, Saba and Su, Rui and Akhtar, Javeed and Shuja, Ahmed and Siddiqi, Humaira M. and El-Shafei, Ahmed}, year={2021}, month={Dec} }
 @article{elmorsy_lyu_su_abdel-latif_badawy_el-shafei_fadda_2020, title={Co-sensitization of the HD-2 complex with low-cost cyanoacetanilides for highly efficient DSSCs}, volume={19}, ISSN={["1474-9092"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85081142495&partnerID=MN8TOARS}, DOI={10.1039/c9pp00381a}, abstractNote={The photophysical and electrochemical properties of new targeted 2-cyanoacetanilide-based dyes are illustrated. New cyanoacetanilides SA7 –10 were synthesized and employed as co-sensitizers in DSSCs. The chemical structures of these 2-cyanoacetanilides differ according to the substituent at the benzene ring (–H, –Me, –OMe and –NEt_2), with the anchoring moiety being the same, a –COOH group. Furthermore, a density functional theory (DFT) calculation has shown an effective intermolecular charge transfer character, the HOMOs of SA7 –10 are mainly located on the corresponding donor part, and their LUMOs are located on carboxylic acid moieties as the acceptor. Interestingly, using photosensitizers SA7 –10 as co-sensitizers with HD-2 dye causes an improvement in their photovoltaic performances. Among the dyes, SA10 co-sensitized with HD-2 displayed an overall efficiency of 8.25%, a J _SC of 19.5 mA cm^−2, a V _OC of 0.65 V and an FF of 64.35 compared to 7.46%, 19 mA cm^−2, 0.64 V and 60.54, respectively, of HD-2 only. Moreover, the electrochemical impedance spectroscopy (EIS) data of SA7 –10 and HD-2 were found to be in accordance with the obtained photovoltaic parameters. Finally, the results indicated that 2-cyanoacetanilide-based dyes were utilized as promising co-sensitizers due to their easy preparation methods and their relatively small size}, number={2}, journal={PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES}, author={Elmorsy, Mohamed R. and Lyu, Luping and Su, Rui and Abdel-Latif, Ehab and Badawy, Safa A. and El-Shafei, Ahmed and Fadda, Ahmed A.}, year={2020}, month={Feb}, pages={281–288} }
 @article{ashraf_su_akhtar_siddiqi_shuja_al-saad_al-qaradawi_el-shafei_2020, title={Investigations into structure-property relationships of novel Ru(II) dyes with N,N '-Diethyl group in ancillary ligand for dye-sensitized solar cells (vol 171, 107754, 2019)}, volume={173}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85073031853&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2019.107955}, journal={DYES AND PIGMENTS}, author={Ashraf, Saba and Su, Rui and Akhtar, Javeed and Siddiqi, Humaira M. and Shuja, Ahmed and Al-Saad, Khalid A. and Al-Qaradawi, Siham Y. and El-Shafei, Ahmed}, year={2020}, month={Feb} }
 @article{elmorsy_su_abdel-latif_badawy_el-shafei_fadda_2020, title={New cyanoacetanilides based dyes as effective co-sensitizers for DSSCs sensitized with ruthenium (II) complex (HD-2)}, volume={31}, ISSN={["1573-482X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85083047076&partnerID=MN8TOARS}, DOI={10.1007/s10854-020-03337-3}, number={10}, journal={JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS}, author={Elmorsy, Mohamed R. and Su, Rui and Abdel-Latif, Ehab and Badawy, Safa A. and El-Shafei, Ahmed and Fadda, Ahmed A.}, year={2020}, month={May}, pages={7981–7990} }
 @article{su_lyu_elmorsy_el-shafei_2020, title={Structural studies and photovoltaic investigation of indolo[2,3-b]quinoxaline-based sensitizers/co-sensitizers achieving highly efficient DSSCs}, volume={44}, ISSN={["1369-9261"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85082978601&partnerID=MN8TOARS}, DOI={10.1039/c9nj04456f}, abstractNote={Novel organic sensitizers were designed and synthesized by employing indolo[2,3-b]quinoxaline (IQ) as the main building block. IPCE graphs indicated that both competition and compensation of photon harvesting co-exist during the co-sensitization.}, number={7}, journal={NEW JOURNAL OF CHEMISTRY}, author={Su, Rui and Lyu, Luping and Elmorsy, Mohamed R. and El-Shafei, Ahmed}, year={2020}, month={Feb}, pages={2797–2812} }
 @article{su_ashraf_lyu_el-shafei_2020, title={Tailoring dual-channel anchorable organic sensitizers with indolo[2,3-b] quinoxaline moieties: Correlation between structure and DSSC performance}, volume={206}, ISSN={["0038-092X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85086470512&partnerID=MN8TOARS}, DOI={10.1016/j.solener.2020.06.020}, abstractNote={Two new metal-free heteroaromatic organic dyes, FS13 and FS14, with D-D|A-(π-A)2 structural configuration were tailored and synthesized as effective dual-channel anchorable sensitizers in DSSCs. The new entities consist of indolo[2,3-b]quinoxaline (IQ) as the constructing unit containing merged donor–acceptor system (D|A) connected to two cyanoacetic acids as anchoring groups via phenylene as π-linker at 2- and 3- positions of IQ rings. Their experimental properties together with theoretical modeling using density functional theory (DFT) are studied to understand their achievability as feasible sensitizers. The photovoltaic performance and charge transfer properties were assessed with illumination condition as 1.5 AM standard. The DFT study revealed that the isodensity of FS13 and FS14 has been slightly shifted towards di-anchors compared to the mono-anchoring FS08, leading to more distinguished charge separation; however, the closely paralleled anchoring branches bring out high spatial hindrance, turning into the less conjugated system and the lower photocurrent. For the study of co-sensitization effect employing dual-channel dyes with HD-2 ruthenium sensitizer, FS14 displayed the most positive co-sensitization effect and enhanced the overall efficiency by 9.2% from 7.50% to 8.67%. For both novel dyes, the considerably improved photovoltage and fill factor are ascribed to the improved coverage percentage on TiO2 surface and the enhancement of dye anti-aggregation and charge recombination resistance, which in turn corroborates the superior affinity of di-anchors. Furthermore, the dark current resistance estimated from impedance graphs employing co-sensitization methodology coincided with the observed photovoltage, indicating the enormous potential of di-anchoring dyes in ameliorating the photovoltaic performance.}, journal={SOLAR ENERGY}, author={Su, Rui and Ashraf, Saba and Lyu, Luping and El-Shafei, Ahmed}, year={2020}, month={Aug}, pages={443–454} }
 @article{lyu_su_al-qaradawi_al-saad_el-shafei_2020, title={Three-component one-pot reaction for molecular engineering of novel cost-effective highly rigid quinoxaline-based photosensitizers for highly efficient DSSCs application: Remarkable photovoltage (vol 171, 107683, 2019)}, volume={173}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85073544248&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2019.107962}, journal={DYES AND PIGMENTS}, author={Lyu, Luping and Su, Rui and Al-Qaradawi, Siham Y. and Al-Saad, Khalid and El-Shafei, Ahmed}, year={2020}, month={Feb} }
 @article{kesavan_attia_su_anees_el-shafei_adhikari_2019, title={Asymmetric Dual Anchoring Sensitizers/Cosensitizers for Dye Sensitized Solar Cell Application: An Insight into Various Fundamental Processes inside the Cell}, volume={123}, ISSN={["1932-7455"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85072953120&partnerID=MN8TOARS}, DOI={10.1021/acs.jpcc.9b06525}, abstractNote={To study the various fundamental processes occurring inside the dye sensitized solar cell (DSSC), we have fabricated devices employing newly synthesized diphenylamine-based organic dyes with A-D-π-A configuration, carrying four different anchoring groups, namely, cyanoacetic acid (DDC), rhodanine acetic acid (DDR), 4-hydrazinylbenzoic acid (DDH), and barbituric acid (DDB), as effective sensitizers/cosensitizers. In the present work, all the bianchoring dyes were subjected to photophysical, electrochemical, thermodynamic, photoelectrochemical, and theoretical studies. All of them displayed characteristic λabs and λemi in the range of 415–480 and 570–680 nm, respectively. Their optical and electrochemical band gaps were calculated to be in the order of 2.1 to 2.3 eV. The calculated driving forces for electron injection (ΔGinj), recombination (ΔGinj), and regeneration (ΔGreg) processes were found to be negative, showing the feasibility of these processes, while their DFT studies clearly indicated the directi...}, number={40}, journal={JOURNAL OF PHYSICAL CHEMISTRY C}, author={Kesavan, Rajalakshmi and Attia, Fathy and Su, Rui and Anees, P. and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2019}, month={Oct}, pages={24383–24395} }
 @article{ashraf_su_akhtar_siddiqi_shuja_al-saad_al-qaradawi_el-shafei_2019, title={Investigations into structure-property relationships of novel Ru(II) dyes with N,N '-Diethyl group in ancillary ligand for dye-sensitized solar cells}, volume={171}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85073088390&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2019.107754}, abstractNote={Structure-property relationships of four novel bipyridyl Ru(II) complexes, denoted as SD-22, SD-24, SD-26 and SD-28, are reported herein. The molecular structures of all four photosensitizers were confirmed using FT-IR, 1H NMR and mass spectrometry. Photovoltaic characteristics of the photosensitizers were evaluated under 1.5 a.m. standard illumination condition, in presence of deoxycholic acid as co-adsorbent, and subsequently compared to the performance of the benchmark, Z907. SD-22 showed an IPCE of 52% and 50% at 440 nm and 550 nm, respectively, a short-circuit photocurrent density (JSC) of 17.37 mA cm−2, open-circuit photovoltage (VOC) of 0.63 V and fill factor (FF) of 0.66, producing an overall conversion efficiency (η) of 7.31%, which outperformed Z907 (7.02%) under the same experimental device conditions. The η of the other photosensitizers is in the following order: SD-22 > SD-28 > SD-26 > SD-24. Photosensitizer SD-22 has N,N′-dialkyl group attached to a benzene ring while SD-24 has N,N′-dialkyl without a benzene ring. The extended conjugation in SD-22 translated into higher overall solar-to-electric conversion efficiency. Substitution of dialkylamino-based ancillary ligands of Ru(II) dyes SD-26 and SD-28 with –OCH3 and –OC6H13 also demonstrated that the photovoltaic performance of polypyridyl ruthenium photosensitizers is a function of the donating power of ancillary ligands as well as the steric effect of alkoxy auxochromes at –ortho position.}, journal={DYES AND PIGMENTS}, author={Ashraf, Saba and Su, Rui and Akhtar, Javeed and Siddiqi, Humaira M. and Shuja, Ahmed and Al-Saad, Khalid A. and Al-Qaradawi, Siham Y. and El-Shafei, Ahmed}, year={2019}, month={Dec} }
 @article{abdel-shakour_el-said_abdellah_su_el-shafei_2019, title={Low-cost Schiff bases chromophores as efficient co-sensitizers for MH-13 in dye-sensitized solar cells}, volume={30}, ISSN={0957-4522 1573-482X}, url={http://dx.doi.org/10.1007/s10854-019-00806-2}, DOI={10.1007/s10854-019-00806-2}, number={5}, journal={Journal of Materials Science: Materials in Electronics}, publisher={Springer Science and Business Media LLC}, author={Abdel-Shakour, M. and El-Said, Waleed A. and Abdellah, Islam M. and Su, Rui and El-Shafei, Ahmed}, year={2019}, month={Feb}, pages={5081–5091} }
 @article{su_ashraf_el-shafei_2019, title={Structure-property relationships: "Double-tail versus double-flap" ruthenium complex structures for high efficiency dye-sensitized solar cells}, volume={177}, ISSN={["0038-092X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85057598963&partnerID=MN8TOARS}, DOI={10.1016/j.solener.2018.11.038}, abstractNote={Six novel heteroleptic amphiphilic polypyridyl Ruthenium (II) complexes, coded FS01-FS06, with hetero-aromatic electron-donor ancillary ligands containing julolidine-derived moieties were synthesized to investigate the relationship between structure modulations of electron donors of Ru(II) dyes and their photophysical, electrochemical and photovoltaic properties for dye-sensitized solar cells (DSSCs). These modulations include: Ru(II) complexes with double “tails” (i.e. tetramethyl groups attached to the end of julolidine-based antennas, FS04) compared to the ones without double “tails” (FS01); complexes with double small “flaps” (i.e. small acyclic electron donor auxochromes ortho to the CH = CH bridge of stilbazole, FS02, FS05) compared to the ones with double large “flaps” (FS03, FS06). Their low energy metal-to-ligand charge transfers (MLCT) band and molar absorptivities were all better than those of the benchmark, N719. It was also shown that the incorporation of double “flaps” into the ancillary ligands caused a slight red shift of light absorption. The photovoltaic properties were evaluated under 1.5 AM standard illumination condition and compared to N719. The highest photocurrent density (JSC) was observed for the complex with double “tails” and double small “flaps” (FS05). The overall conversion efficiency for devices employing julolidine-derived Ru (II) complexes was in the following order FS05 > FS02 > FS04 > FS01 > FS06 > FS03. FS05 (8.16%) outperformed the benchmark N719 (7.75%) in the photovoltaic performance, which is due to its best light-harvesting ability, highest molar extinction coefficient and smallest energy band gap among all the six dyes. To probe the interrelationship among julolidine-based electron donors of ancillary ligands, photocurrent and photovoltage of these dyes, the equilibrium molecular geometries of the ancillary ligands were calculated using DFT. The equilibrium molecular geometries of these dyes the photocurrent and photovoltage are dependent on the donating effect of alkyloxy auxochromes, the steric effect generated from the auxochromes and julolidine moieties, and the orientation of longer alkyloxy group. The introduction of double “tails” resulted in less dye aggregation and higher charge recombination resistance, leading to higher photocurrents and photovoltages in the solar cell performances. Despite of the donating effect of alkyloxy groups, the bulky double “flaps” mainly jammed the hole transportation between the redox couple of the electrolyte and the HOMO of thiocyanate groups (−NCS), translating into the decrease of photocurrent.}, journal={SOLAR ENERGY}, author={Su, Rui and Ashraf, Saba and El-Shafei, Ahmed}, year={2019}, month={Jan}, pages={724–736} }
 @article{lyu_su_al-qaradawi_al-saad_el-shafei_2019, title={Three-component one-pot reaction for molecular engineering of novel cost-effective highly rigid quinoxaline-based photosensitizers for highly efficient DSSCs application: Remarkable photovoltage}, volume={171}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85068505054&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2019.107683}, abstractNote={A simple three-component one-pot approach was developed to generate three novel highly rigid quinoxaline-based dyes, which were further investigated as sensitizers of dye-sensitized solar cells (DSSCs). The effect of different push-pull molecular motifs containing various donors and attachment of long alkyl chains on photophysical, electrochemical and photovoltaic performances, along with theoretical calculations were studied comprehensively. In particular, LY03-based DSSCs showed the highest efficiency of 7.04% with a short-circuit photocurrent density (JSC) of 14.32 mA cm−2, an open-circuit photovoltage (VOC) of 910 mV and a fill factor (FF) of 0.54% under AM 1.5 irradiation (100 mW cm−2). The results confirm that improving the molecular rigidity of sensitizer and incorporation of long alkyl chains into an auxiliary acceptor and donor is one of the most effective pathways to prevent “trade-off” effect, which translated into remarkable improvement in open-circuit photovoltage of 0.91 V, hence, enhancing the photovoltaic performance.}, journal={DYES AND PIGMENTS}, author={Lyu, Luping and Su, Rui and Al-Qaradawi, Siham Y. and Al-Saad, Khalid A. and El-Shafei, Ahmed}, year={2019}, month={Dec} }
 @article{elmorsy_su_fadda_etman_tawfik_el-shafei_2018, title={Effect of terthiophene spacer position in Ru(II) bipyridyl complexes on the photocurrent and photovoltage for high efficiency dye-sensitized solar cells}, volume={156}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85045755836&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2018.04.005}, abstractNote={Two novel ruthenium complexes, MR-1 and MR-2 were synthesized for use in dye-sensitized solar cells (DSSCs). Under similar fabrication conditions, the photovoltaic performances of these dyes were evaluated and compared to the standard ruthenium complex N719. MR-1 and MR-2 showed the efficiencies of 8.19% and 5.32%, respectively, while N719 achieved 7.66%. MR-1 also displayed higher VOC than MR-2, which is due to the larger molecular size and higher molar extinction coefficient of the former, which translates into less dye aggregation on a thinner film of TiO2. Incorporation of terthiophene as a linker reduces the band gap of MR-1 when compared to that of MR-2. The influence of π-conjugated bridge on optical and electrochemical properties was investigated. Results demonstrated that the absorption band of MR-1 displayed higher extinction coefficient with a broader absorption compared to MR-2 and the benchmark Ru(II) dye, N719, due to the enhancement of electron donating ability of π-conjugated bridge.}, journal={DYES AND PIGMENTS}, author={Elmorsy, Mohamed R. and Su, Rui and Fadda, Ahmed A. and Etman, H. A. and Tawfik, Eman H. and El-Shafei, Ahmed}, year={2018}, month={Sep}, pages={348–356} }
 @article{naik_abdellah_abdel-shakour_su_keremane_el-shafei_adhikari_2018, title={Improvement in performance of N3 sensitized DSSCs with structurally simple aniline based organic co-sensitizers}, volume={174}, ISSN={["0038-092X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85054333887&partnerID=MN8TOARS}, DOI={10.1016/j.solener.2018.09.071}, abstractNote={In this work, we report comprehensive photovoltaic investigation of four structurally simple D-A configured organic dyes, A1-4 as active co-sensitizers in DSSCs sensitized with well-known Ru (II) based N3 dye. These effective co-sensitizers (A1-4) comprise N,N-dimethylaniline ring as donor scaffold linked with electron withdrawing functionalities, viz. barbituric acid (A1), N,N-dimethyl barbituric acid (A2), thiobarbituric acid (A3), and N,N-diethyl thiobarbituric acid (A4) as acceptor/anchoring units. In the present study, for the first time we have demonstrated the profound role of various simple organic molecules carrying different heterocyclic anchoring units on the photovoltaic parameters of the N3 sensitized devices. Also, the effect of concentration of sensitizer/co-sensitizers on the device performance characteristics has been investigated in depth. From the results, it is evident that, the device fabricated using co-sensitizer A2 carrying N,N-dimethyl barbituric acid along with sensitizer N3 in all concentrations outperformed when compared to N3 alone or other co-sensitizers. Interestingly, the best photovoltaic performance was obtained for the co-sensitized device fabricated using 0.3 mM co-sensitizer A2 along with 0.2 mM of N3 sensitizer. It displayed PCE of 7.02% with JSC of 15.27 mA·cm−2, VOC of 0.671 V and FF of 68.47%. Thus, the observed results have thrown new light upon the device optimization to yield DSSCs with improved performance by the selection of matchable co-sensitizers at appropriate concentrations.}, journal={SOLAR ENERGY}, author={Naik, Praveen and Abdellah, Islam M. and Abdel-Shakour, M. and Su, Rui and Keremane, Kavya S. and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2018}, month={Nov}, pages={999–1007} }
 @article{su_elmorsy_abed_islam_lord_fadda_el-shafei_2017, title={A Comparative Study on Two Ru-II Complexes with Thiophene-Based Ancillary Ligands for High-Efficiency Dye-Sensitized Solar Cells}, volume={2017}, ISSN={["1099-0682"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85028060292&partnerID=MN8TOARS}, DOI={10.1002/ejic.201700468}, abstractNote={Heteroleptic polypyridyl Ru complexes MMR‐1 and MMR‐2 containing 2‐(methylthio)thienyl and 2‐(4‐methoxyphenyl)thienyl units on the antennas of ancillary ligands, respectively, were designed, synthesized, and characterized as sensitizers for dye‐sensitized solar cells. The maximum absorption wavelength of MMR‐1 is more red‐shifted than that of MMR‐2, but MMR‐2 has a higher molar extinction coefficient, leading to better light harvesting. Under the same device‐fabrication conditions, the photovoltaic performances of these sensitizers were evaluated while anchored on mesoporous TiO2 and compared to that of the benchmark N719. Both MMR‐1 and MMR‐2 exhibited comparable or even higher solar‐to‐electric conversion efficiencies η with respect to N719 when employed as photosensitizers in DSSCs. Compared to MMR‐1, MMR‐2 exhibited better overall conversion efficiency, which was attributed to the electron‐donating effect of the 4‐methoxyphenyl group and the better absorptivity by harvesting higher‐energy photons. Complex MMR‐2 also showed higher open‐circuit voltage VOC than MMR‐1, which is likely due to the extension of the antenna of the ancillary ligand by inserting a phenyl group, which leads to less dye aggregation. The photovoltaic performance of MMR‐2 was better, with a short‐circuit photocurrent density of 16.76 mA cm–2, a VOC of 0.673 V, a fill factor of 73.5 %, and an η value of 8.29 % with the addition of 0.5 m 4‐tert‐butylpyridine (TBP) compared to 8.18 % for N719.}, number={31}, journal={EUROPEAN JOURNAL OF INORGANIC CHEMISTRY}, author={Su, Rui and Elmorsy, Mohamed R. and Abed, Mira and Islam, Ashraful and Lord, Meghan and Fadda, Ahmed A. and El-Shafei, Ahmed}, year={2017}, month={Aug}, pages={3690–3697} }
 @article{naik_su_elmorsy_babu_el-shafei_adhikari_2017, title={Molecular design and theoretical investigation of new metal-free heteroaromatic dyes with D-pi-A architecture as photosensitizers for DSSC application}, volume={345}, ISSN={["1010-6030"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85019870789&partnerID=MN8TOARS}, DOI={10.1016/j.jphotochem.2017.05.033}, abstractNote={Herein, we report design, synthesis and photovoltaic performance of four new metal-free heteroaromatic dyes (P1-4) with D-π-A architecture carrying electron donating carbazole core connected to four different electron withdrawing/anchoring groups, viz. cyanoacetic acid, rhodanine-3-acetic acid, barbituric acid and thiobarbituric acid and phenylene ring as a π-spacer. The newly designed P1-4 were synthesized from carbazole derivative using Suzuki cross coupling approach followed by Knoevenagel condensation reaction. Their structures were confirmed by FTIR, NMR, Mass spectral and elemental analyses. The dyes were subjected to optical and electrochemical studies in order to investigate their absorption/emission behavior as well as HOMO/LUMO energies. The UV–vis spectral studies reveal that the P1-4 showed λmax at 412, 439, 458 and 489 nm, respectively. Their optical band-gap is in the range of 2.17 to 2.61 eV and fluorescence quantum yield is in the order of 44–70%. From energy level diagram, it is clear that all the dyes possess good thermodynamic feasibility for electron injection into CB edge of TiO2 as well as their regeneration from electrolyte system. The photovoltaic performance studies indicate that among the tested dyes, P1 anchored with cyanoacetic acid displayed the highest IPCE (32%), resulting in improved PCE (1.94%), JSC (4.68 mA cm−2), VOC (0.588 V) and FF (70.3%) values, when compared to other dyes. Finally, DFT studies were performed using Turbomole 7.1 V software to investigate their electron cloud delocalization in HOMO/LUMO levels and theoretical absorption spectral data. The results reveal that the dye P1 showed effective charge separation in its FMO levels, which has reflected in its ICT behavior and hence P1 displayed the improved photovoltaic performance.}, journal={JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY}, author={Naik, Praveen and Su, Rui and Elmorsy, Mohamed R. and Babu, Dickson D. and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2017}, month={Aug}, pages={63–73} }
 @article{naik_elmorsy_su_babu_el-shafei_adhikari_2017, title={New carbazole based metal-free organic dyes with D-pi-A-pi-A architecture for DSSCs: Synthesis, theoretical and cell performance studies}, volume={153}, ISSN={["0038-092X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85020822743&partnerID=MN8TOARS}, DOI={10.1016/j.solener.2017.05.088}, abstractNote={Herein we report the design, synthesis and photovoltaic performance studies of three new D-π-A-π-A architectured organic chromophores (N1-3) derived from (Z)-3-(9-hexyl-9H-carbazol-3-yl)-2-(thiophen-2-yl) acrylonitrile scaffold. In the new design, the electron rich carbazole unit is connected to three different electron withdrawing/anchoring species, viz. cyano acetic acid, rhodanine-3-acetic acid and barbituric acid via cyano vinyl thiophene as π-spacer. Newly synthesized dyes were characterized by spectral, photophysical and electrochemical analyses. Their optical band-gap, GSOP and ESOP values, as calculated from the optical and CV studies were found to be in the range of 2.12–2.21, −5.52 to −5.43 and −5.40 to −3.25 eV respectively. The DFT and TD-DFT studies were performed using Turbomole 7.1V software and the results indicated the existence of proper charge separation between HOMO and LUMO levels of the dyes. Also, the results revealed good matching of theoretically generated optical spectral data with the experimental values. Finally, DSSC devices were fabricated using these three dyes and the dye N1 containing cyanoacetic acid as an acceptor unit showed better photo conversion efficiency (η) of 3.55% than the other two dyes. It’s JSC, VOC, and IPCE parameters were shown to be 9.06 mA cm−2, 0.577 V and 48%, respectively. The obtained EIS data and electron lifetimes of N1–3 sensitized devices are well in accordance with experimental photovoltaic parameters.}, journal={SOLAR ENERGY}, author={Naik, Praveen and Elmorsy, Mohamed R. and Su, Rui and Babu, Dickson D. and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2017}, month={Sep}, pages={600–610} }
 @article{naik_su_babu_el-shafei_adhikari_2017, title={Structurally simple D-A-type organic sensitizers for dye-sensitized solar cells: effect of anchoring moieties on the cell performance}, volume={14}, ISSN={["1735-2428"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85032027118&partnerID=MN8TOARS}, DOI={10.1007/s13738-017-1180-3}, number={11}, journal={JOURNAL OF THE IRANIAN CHEMICAL SOCIETY}, author={Naik, Praveen and Su, Rui and Babu, Dickson D. and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2017}, month={Nov}, pages={2457–2466} }
 @article{babu_su_naik_el-shafei_adhikari_2017, title={Synthesis and photovoltaic performance of a novel asymmetric dual channel co-sensitizer for dye-sensitized solar cell beyond 10% efficiency}, volume={141}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85012243986&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2017.02.010}, abstractNote={In this paper, we report the design and synthesis of a new bi-anchoring indole based co-sensitizer DBA-8 with A-π-D-A (acceptor-π bridge-donor-acceptor) architecture, carrying indole moiety as a donor and barbituric acid as acceptor/anchoring groups. Its photo-physical and electrochemical properties along with molecular geometries, calculated from Density Functional Theory (DFT) are employed to comprehend the effect of co-sensitizer structure on photovoltaic characteristics of DSSCs. The abovementioned organic dye (DBA-8) was employed as a co-sensitizer along with well-known ruthenium based sensitizer NCSU-10 in order to broaden the spectral responses of the co-sensitized DSSC. In the present work, for the first time we are demonstrating the profound role of a dual-anchoring co-sensitizer that can play in ameliorating the overall performance of a solar cell. The photovoltaic studies indicated that, the co-sensitizer DBA-8 succeeded in increasing the light harvesting ability in the device significantly. Notably, the device co-sensitized using 0.2 mM DBA-8 along with ruthenium based chromophore NCSU-10, showed a maximum efficiency of 10.68% (Jsc = 25.14 mAcm−2, Voc = 0.695 V, ff = 61.2%). Further, the good agreement between the theoretically and experimentally obtained λmax data vindicate that, the energy functional and basis set employed in this study can be successfully utilized for predicting the absorption spectra of new photosensitizers, with great precision before synthesis. Furthermore, all these findings showcase the vast potential of bi-anchoring molecules in improving the overall performance of the dye-sensitized solar cells.}, journal={DYES AND PIGMENTS}, author={Babu, Dickson D. and Su, Rui and Naik, Praveen and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2017}, month={Jun}, pages={112–120} }