@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{sun_lyu_elmorsy_el-shafei_2019, title={Novel metal-free organic dyes constructed with the D-D vertical bar A-pi-A motif: Sensitization and co-sensitization study}, volume={194}, ISSN={["0038-092X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85074473045&partnerID=MN8TOARS}, DOI={10.1016/j.solener.2019.10.061}, abstractNote={A new structural motif, D-D|A-π-A, was suggested for the design of novel metal-free organic sensitizers, where “D|A” represents a fused donor-acceptor conjugated building block. Three organic dyes, coded FS07, FS08 and FS09, were synthesized accordingly with the incorporation of indolo [2,3-b] quinoxaline (IQ) as the main building block but different additional donors. The synthesized dyes were well-characterized and their photophysical and electrochemical properties were well-studied. Additionally, molecular modeling via DFT method was employed to probe their photovoltaic behaviors as sensitizers/co-sensitizers. The isodensity of the molecular orbitals displays the distinguished intramolecular charge delocalization in the IQ moiety, even though its donor and acceptor sections are coplanar-fused. In the photovoltaic characterization, FS08 exhibited the best DSSC performance. Moreover, FS07, FS08 and FS09 were co-sensitized along with a typical high efficient bipyridyl Ru(II) sensitizer, HD-2, in order to induce the light harvesting over expanded spectral region and hence improve the efficiency. The solar cell co-sensitized with FS08 displayed improved efficiency of 7.94% with JSC of 19.37 mA⋅cm−2, VOC of 0.654 V and FF of 62.7%, which outperformed the device employing HD-2 alone (efficiency of 7.46%). Owing to the appropriate dye loading of FS08 in the presence of HD-2 and CDCA mixed dye solution, the benign coordination for light harvesting was guaranteed and the photoexcitation was maximized, the co-sensitized JSC was improved; due to the well-modified TiO2 surface coverage with the tight attachment of FS08 and HD-2, the dye aggregation was diminished and the undesired charge recombination was suppressed, the co-sensitized VOC was improved.}, journal={SOLAR ENERGY}, author={Sun, Rui and Lyu, Luping and Elmorsy, Mohamed R. and El-Shafei, Ahmed}, year={2019}, month={Dec}, pages={400–414} }
 @article{naik_su_elmorsy_el-shafei_adhikari_2018, title={Investigation of new carbazole based metal-free dyes as active photo-sensitizers/co-sensitizers for DSSCs}, volume={149}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85030704247&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2017.09.068}, abstractNote={Herein, we report the molecular design, synthesis and characterization of three new D-D-π-A configured metal-free chromophores D1-3 for their application in DSSCs as sensitizers as well as co-sensitizers. The new entities comprise carbazole as donor scaffold, 4-methoxyphenyl group as auxiliary donor and three different units, viz. cyanoacetic acid, 2, 4-thiazolidinedione and barbituric acid as acceptor/anchoring groups. Their photochemical, electrochemical and theoretical studies were carried out in order to assess their feasibility as active sensitizers. Further, D1-3 were exploited as co-sensitizers along with NCSU-10 dye. Their photoelectrochemical performances and charge transport properties in fabricated DSSCs were studied. The results revealed that D1 sensitizer displayed the highest PCE of 2.20% among the three dyes. D3 when co-sensitized with NCSU-10 displayed an improved PCE of 8.32% (JSC = 19.25 mA.cm−2, VOC = 0.680 V, FF = 63.7%) while NCSU-10 alone exhibited PCE of 8.25% (JSC = 20.41 mA.cm−2, VOC = 0.667 V, FF = 60.6%).}, journal={DYES AND PIGMENTS}, author={Naik, Praveen and Su, Rui and Elmorsy, Mohamed R. and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2018}, month={Feb}, pages={177–187} }
 @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} }