MDACl2-Modified SnO2 Film for Efficient Planar Perovskite Solar Cells

Abstract

The electron transport layer (ETL) with excellent charge extraction and transport ability is one of the key components of high-performance perovskite solar cells (PSCs). SnO2 has been considered as a more promising ETL for the future commercialization of PSCs due to its excellent photoelectric properties and easy processing. Herein, we propose a facile and effective ETL modification strategy based on the incorporation of methylenediammonium dichloride (MDACl2) into the SnO2 precursor colloidal solution. The effects of MDACl2 incorporation on charge transport, defect passivation, perovskite crystallization, and PSC performance are systematically investigated. First, the surface defects of the SnO2 film are effectively passivated, resulting in the increased conductivity of the SnO2 film, which is conducive to electron extraction and transport. Second, the MDACl2 modification contributes to the formation of high-quality perovskite films with improved crystallinity and reduced defect density. Furthermore, a more suitable energy level alignment is achieved at the ETL/perovskite interface, which facilitates the charge transport due to the lower energy barrier. Consequently, the MDACl2-modified PSCs exhibit a champion efficiency of 22.30% compared with 19.62% of the control device, and the device stability is also significantly improved.

Vertically Aligned Nanowires and Quantum Dots: Promises and Results in Light Energy Harvesting

“…In this context, the effect of interpenetrating ZnO NWs does not seem to be so positive if only the best overall efficiency results are sought. For example, in [ 117 , 118 ], using as ETL, respectively, a CuCl /MDACl superficially modified tin oxide planar film, PCEs of 20.3% and 22.3% were obtained as the best efficiency values, even with excellent temporal stability and reversible behavior. Moreover, as can be seen in Table 3 , the efficiency of perovskite solar cells using NWs (all ZnO–based) does not exceed the threshold of 20%.…”

Multifunctional Interface Treatment of Phosphate for High-Efficiency Perovskite Solar Cells

“…To date, various physical or chemical methods have been proven effective in interface passivation, leading to significant improvements in the ETL/perovskite interface and overall device performance. − Interface passivation involves the direct coating of materials, such as the ionic liquids, organic polymers, self-assembled monolayer, and small molecules , onto the SnO 2 surface as an interfacial buffer layer between SnO 2 and the perovskite film. − This passivation technique effectively reduces trap defects and improves the stability of PSCs through interactions between defect charges and the uncoordinated ionic components within the interfacial layer. Nevertheless, these strategies have certain limitations.…”