LAUSR

In the fabrication of inverted perovskite solar cells (PeSCs), it is necessary to select an appropriate p-type semiconductive material as hole transport layer (HTL), which will determine the crystallization quality of the subsequent perovskite films and hole charge extraction at the perovskite/HTL interface. Herein, a low-cost, low-temperature processed, and hydrophobic organic small molecule, N,N-bis(3-methylphenyl)-N,N-bis(phenyl) benzidine (TPD), is utilized as HTL in fabricating inverted PeSCs. It achieves a peak power conversion efficiency of 19.77% by optimizing the thickness, which is about 1.4 times higher than the PeSCs employing poly(3,4-ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT:PSS) as HTL. Compared with PEDOT:PSS-based PeSCs, the outstanding performance of PeSCs-based TPD derives from that of the employment of TPD as the HTL produced perovskite films with larger grain size and higher crystallinity. Owing to the hydrophobicity of TPD, TPD-based PeSCs exhibited longer stability. After storage of 700 h, the PeCE of TPD-based PeSCs retains 84.1%.