Indolo[3,2-b]indole-based crystalline hole-transporting material for highly efficient perovskite solar cells†
Illhun Cho,Nam Joong Jeon,Oh Kyu Kwon,Dong Won Kim,Eui Hyuk Jung,Jun Hong Noh,Jangwon Seo,Soo Young Park
Chemical Science Pub Date : 09/05/2016 00:00:00 , DOI:10.1039/C6SC02832B
Abstract

We have designed and synthesized fluorinated indolo[3,2-b]indole (IDID) derivatives as crystalline hole-transporting materials (HTM) for perovskite solar cells. The fluorinated IDID backbone enables a tight molecular arrangement stacked by strong π–π interactions, leading to a higher hole mobility than that of the current HTM standard, p,p-spiro-OMeTAD, with a spherical shape and amorphous morphology. Moreover, the photoluminescence quenching in a perovskite/HTM film is more effective at the interface of the perovskite with IDIDF as compared to that of p,p-spiro-OMeTAD. As a consequence, the device fabricated using IDIDF shows superior photovoltaic properties compared to that using p,p-spiro-OMeTAD, exhibiting an optimal performance of 19%. Thus, this remarkable result demonstrates IDID core-based materials as a new class of HTMs for highly efficient perovskite solar cells.

Graphical abstract: Indolo[3,2-b]indole-based crystalline hole-transporting material for highly efficient perovskite solar cells