Molecular Interaction Regulates the Performance and Longevity of Defect Passivation for Metal Halide Perovskite Solar Cells

Abstract

Defect passivation constitutes one of the most commonly used strategies to fabricate highly efficient perovskite solar cells (PSCs). However, the durability of the passivation effects under harsh operational conditions has not been extensively studied regardless of the weak and vulnerable secondary bonding between the molecular passivation agents and perovskite crystals. Here, we incorporated strategically designed passivating agents to investigate the effect of their interaction energies on the perovskite crystals and correlated these with the performance and longevity of the passivation effects. We unraveled that the passivation agents with a stronger interaction energy are advantageous not only for effective defect passivation but also to suppress defect migration. The prototypical PSCs treated with the optimal passivation agent exhibited superior performance and operational stability, retaining 81.9 and 85.3% of their initial performance under continuous illumination or nitrogen at 85 °C after 1008 h, respectively, while the reference device completely degraded during that time. This work provides important insights into designing operationally durable defect passivation agents for perovskite optoelectronic devices.

Extension of In-Gap Electronic-State Spectrum Extraction Technique Based on Transient Photo-Voltage Measurement

“…E c denotes the conduction band minimum [24][25][26][27][28] . They predicted that TPV result is linear, which satisfies ln n =AV ph +B (1) Here, [24][25][26][27][28] .…”

“…The density of trap states (DOS T ) distribution is one of the most important factors determining the power conversion efficiency (PCE) of perovskite solar cells (PSCs) [1][2][3][4][5][6] . It affects the carrier recombination and transport to hinder the enhancement of PCE [7][8][9][10] .…”

“…It affects the carrier recombination and transport to hinder the enhancement of PCE [7][8][9][10] . Recent years, people focus on the study of trap passivation [1][2][3][4][5] .…”

“…It affects the carrier recombination and transport to hinder the enhancement of PCE 7-Trap passivation reduces the amount of trap states to improve the PCE. To evaluate the passivation efficiency, we need to calculate the DOS T distributions of devices with and without passivation for compare 1,2,4,6 . There are few breakthroughs made in the DOS T extraction.…”

Thiamine additive engineering enables improved film formation towards high efficiency and moisture stability in perovskite solar cells

“…Currently, the highest certified power conversion efficiency (PCE) of devices has reached 25.5% [1]. However, the instability of the perovskite layer in the ambient environment (light illumination, heat treatment or moisture erosion) [2][3][4][5], and the existing defects seriously restrict the performance and limit its development towards practical applications and commercialization [6][7][8][9][10]. Among the various environmental factors that cause instability, moisture instability is a major obstacle because of its severe harmfulness, which causes hydrate formation, promoting the irreversible decomposition of perovskite accompanied by a sharp decline in optical absorption and severe electron-hole recombination [11,12].…”