Hole-Transporting Materials Incorporating Carbazole into piro-Core for Highly Efficient Perovskite Solar Cells
Xiang-Dong Zhu a, Xing-Juan Ma b, Ya-Kun Wang a, Yun Li a, Chun-Hong Gao b, Zhao-Kui Wang a,*, Zuo-Quan Jiang a,*, and Liang-Sheng Liao a
a Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, PR China.
b School of Physical Science and Technology, Southwest University, 400715, Chongqing, China.
Hole-transporting materials (HTMs) play a significant role in hole transport and extraction for perovskite solar cells (PeSCs). As an important type of HTMs, the spiro-architecture based material is widely used as small organic HTM in PeSCs with good photovoltaic performances. The skeletal modification of spiro-based HTMs is a critical way of modifying energy level and hole mobility. Thus, many spiro-alternatives were developed to optimize the spiro-type HTMs. Herein, we have designed and prepared a novel carbazole-based single-spiro-HTM named SCZF-5 for efficient PeSCs. In addition, another single-spiro HTM SAF-5 with reported 10-phenyl-10H-spiro[acridine-9,9'-fluorene] (SAF) core was also synthesized for comparison. Through varying from SAF core to SCZF core as well as comparing with the classic 9,9’-spiro-bifluorene, we find the new HTM SCZF-5 exhibits more impressive power conversion efficiency (PCE) of 20.10% than SAF-5 (13.93%) and the commercial HTM spiro-OMeTAD (19.11%). On the other hand, the SCZF-5 based device also has better durability in lifetime testing, indicating the newly designed SCZF by integrating carbazole into the spiro concept has good potential in developing effective HTMs.