Application of Small Molecule based on Dithienogermole core in Bulk Heterojunction Organic Solar Cells and Perovskite Solar Cells
We report the synthesis and characterization of dithienogermole (DTGe) based small molecule named as Ge-PO-2CN, as a donor material for bulkheterojunction (BHJ) organic solar cells (OSCs) and hole transport material (HTM) for dopant free perovskite solar cells. The molecule comprising planar highly resonance and electron rich DTGe core is covalently linked with electron rich phenoxazine, and electron-deficient malononitrile as an end group. This molecule was synthesized by the facile synthetic protocol, without using costly and complicated purification techniques. The Ge-PO-2CN compound has suitable HOMO level in respect to the valance band of the perovskite absorber and BHJ OSCs. The BHJ OSCs device made with Ge-PO-2CN as donor and PC71BM as an acceptor results in power conversion efficiency (PCE) of 5.4%, subsequently the PSC with and active area of 1.02 cm2 made with dopant free Ge-PO-2CN as HTM achieved a PCE up to 11.63%.