Multifunctional <scp>CNT</scp>:<scp>TiO<sub>2</sub></scp> additives in <scp>spiro‐OMeTAD</scp> layer for highly efficient and stable perovskite solar cells
Qiang Lou, Huilin Li, Qingsong Huang, Zhitao Shen, Fumin Li, Qingguo Du, Mengqi Jin, Chong Chen
Abstract
Abstract Hole transport layer (HTL) is very important for the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs). As current state‐of‐the‐art HTL, Li‐TFSI doped spiro‐OMeTAD often suffers low conductivity and the hydrolysis of the additive Li‐TFSI, which significantly hinders the further improvement of PCE of PSCs. Besides, conventional spiro‐OMeTAD has no functional of directly passivating the perovskite crystal defects. Herein, multifunctional TiO 2 nanoparticles (NPs)‐modified CNT (CNT:TiO 2 ) doped spiro‐OMeTAD (spiro‐OMeTAD+CNT:TiO 2 ) HTL is reported for the first time. The incorporated CNT:TiO 2 not only significantly increases the conductivity of spiro‐OMeTAD+CNT:TiO 2 , but also effectively passivates the crystal defects of perovskite layer. The optimized PSCs with spiro‐OMeTAD+CNT:TiO 2 HTL achieved a peak PCE of 21.53%, much higher than that (17.90%) of the conventional spiro‐OMeTAD based PSCs and also show significantly improved stability. image