Highly efficient organic indolocarbazole dye in different acceptor units for optoelectronic applications-a first principle study

A series of novel organic dyes (ICZA1, ICZA2, ICZA3, ICZA4) with D-pi-A structural configuration incorporating indolo[3,2,1-jk]carbazole moiety as donor (D) unit, thiophene as pi-linker and 2-cyanoacrylic acid as acceptor unit were investigated using density functional theory (DFT) and time-dependent DFT (TD-DFT) methods. Indolo[3,2,1-jk]carbazole-based D-pi-A dyes composed of different acceptor groups were designed. By modulating acceptor unit, the efficiency of D-pi-A dye-based dye-sensitized solar cells (DSSCs) can be further improved. In the present work, four novel push-pull organic dyes only differing in electron acceptor, have been designed based on the experimental literature value of IC-2. In order to further improve the light harvesting capability of indolo[3,2,1-jk]carbazole dyes, the acceptor influence on the dye performance were examined. The NLO property of the designed dye molecules can be derived as polarizability and hyperpolarizability. The calculated value of ICZA2 dye is the best candidate for NLO properties. Furthermore, the designed organic dyes exhibit good photovoltaic performance of charge transfer characteristics, driving force of electron injection, dye regeneration, global reactivity, and light harvesting efficiency (LHE). From the calculated value of ICZA4 dye, it has been identified as a good candidate for DSSCs applications. Finally, it is concluded that the both ICZA2 and ICZA4 dyes theoretically agrees well with the experimental value of IC-2 dye. Hence, the dyes ICZA2 and ICZA4 can serve as an excellent electron withdrawing groups for NLO and DSSCs applications.