The crystallinity of organic–inorganic hybrid lead halide perovskite active layers is critical to the performance of perovskite solar cells (PSCs). However, it is a challenge to control the crystallization process of perovskite films by solution process. Here, the fabrication of high‐efficiency PSCs by employing lead acetate (PbAc2) as an additive in the perovskite precursor is demonstrated for the first time. By adding a few percent of PbAc2 (molar ratio with respect to PbI2) into the precursors, the perovskite crystallization process is significantly retarded, leading to pinhole‐free perovskite films with large grains and low defect densities. As result, the power conversion efficiencies and stability of the PSCs are substantially improved. This work provides a convenient and unique approach for preparing high‐quality perovskite films that can be used in photovoltaics as well as other optoelectronic devices.

Highly efficient planar heterojunction (PHJ) perovskite solar cells (PSCs) with a structure of ITO/ PEDOT:PSS/CH 3 NH 3 PbI 3 /PCBM/Al were fabricated by a low-temperature solution process. As employed silica-coated gold (Au@SiO 2 ) nanorods at the interface between the hole transport layer PEDOT:PSS and the active layer CH 3 NH 3 PbI 3 , the average power conversion efficiency (PCE) showed over 40% enhancement, of which the average PCE was improved from 10.9% for PHJ-PSCs without Au@SiO 2 to 15.6% for PHJ-PSCs with Au@SiO 2 , and the champion one up to 17.6% was achieved. Both experiment and simulation results proved that prominent efficiency enhancement comes from the localized surface plasmon resonance of Au@SiO 2 nanorods which could improve the incident light trapping as well as improve the transport and collection of charge carrier, resulting in the enhancement in device parameters. The results suggest that metal nanorods, e.g., Au@SiO 2 , could be employed to fabricate highefficiency and low-cost PHJ-PSCs.

No abstract

No abstract