Enhanced efficiency of the Sb<sub>2</sub>Se<sub>3</sub> thin-film solar cell by the anode passivation using an organic small molecular of TCTA
Yujie Hu, Zhixiang Chen, Yi Xiang, Chuanhui Cheng, Weifeng Liu, Weishen Zhan
Abstract
Abstract Antimony selenide (Sb 2 Se 3 ) is an emerging solar cell material. Here, we demonstrate that an organic small molecule of 4, 4', 4''-tris(carbazol-9-yl)-triphenylamine (TCTA) can efficiently passivate the anode interface of the Sb 2 Se 3 solar cell. We fabricated the device by the vacuum thermal evaporation, and took ITO/TCTA (3.0 nm)/Sb 2 Se 3 (50 nm)/C 60 (5.0 nm)/Alq 3 (3.0 nm)/Al as the device architecture, where Alq 3 is the tris(8-hydroxyquinolinato) aluminum. By introducing a TCTA layer, the open-circuit voltage is raised from 0.36 to 0.42 V, and the power conversion efficiency is significantly improved from 3.2% to 4.3%. The TCTA layer not only inhibits the chemical reaction between the ITO and Sb 2 Se 3 during the annealing process but it also blocks the electron diffusion from Sb 2 Se 3 to ITO anode. The enhanced performance is mainly attributed to the suppression of the charge recombination at the anode interface.