A Modulated Double‐Passivation Strategy Toward Highly Efficient Perovskite Solar Cells with Efficiency Over 21%

Abstract

Material passivation is essential to enhance the quality of perovskite materials and boost the performance of perovskite solar cells (PSCs). However, most of the previous reports only paid attention to improving the quality of perovskite films by adopting single passivation. Here, a facile strategy that can carry out double passivation to improve the performance of PSCs is demonstrated. By using the dilute halide salt PEABr solution to treat the perovskite film, PbI 2 can precipitate from the perovskite. Both PEABr and PbI 2 can passivate the perovskite film, and by combining PEABr and PbI 2 , the double passivation improves the performance of PSCs significantly. Very high short-circuit current density of 24.30 mA cm À2 , open-circuit voltage of 1.10 V, and fill factor of 79.75% are achieved which lead to a surprising efficiency of 21.32% for the passivated device. The improved efficiency is mainly according to the available surface passivation of the perovskite material, leading to repressed nonradiative recombination and unhindered charge collection. In addition, the passivated device exhibits better power conversion efficiency stability relative to the control device.

Two birds with one stone: dual grain-boundary and interface passivation enables >22% efficient inverted methylammonium-free perovskite solar cells

“…Next to dual passivation by PEACl, we first evaluated the effect on the V OC upon employing PEAI and PEABr, since they have been used in numerous previous reports for passivation of perovskite films. 62,65,69,77,99,103 As shown in Fig. S8, PEACl-based GBP&SP PSCs show a much higher average of V OC of ~1.15 V as compared to ~1.12 V in case of PEAI and PEABr.…”

Annealing‐Free, High‐Performance Perovskite Solar Cells by Controlling Crystallization via Guanidinium Cation Doping

“…Here, SCLC in Figure a is used to evaluate the assumption that an enlarged grain size usually implied lower defects density. The defect density is estimated by Equation () where is the trap density, e is the elementary charge of the unit electron, L is the thickness of perovskite film (probably around 500 nm), ε is the relative dielectric constants of perovskite (assume to be 6.5), [ 37 ] is the vacuum permittivity, and is the trap‐filled limit voltage extracted from the dark J–V curve of the electron‐only device. Significantly, value intercepted from the SCLC measurement in Figure 4a was 0.29 V for the GAI‐doped device.…”

Boosting perovskite nanomorphology and charge transport properties via a functional D–π-A organic layer at the absorber/hole transporter interface

“…Since the grain boundaries are considered to act as charge recombination sites, their repression entails improved charge transport and collection at the interface of the perovskite film, leading possibly to higher FF value. 45 The grain size distribution was estimated by the statistical analysis shown in Fig. S7, † where the size distribution of a representative (N = 100) number of perovskite grains from each sample is presented.…”