Deciphering the Morphology Change and Performance Enhancement for Perovskite Solar Cells Induced by Surface Modification

Abstract

Organic–inorganic perovskite solar cells (PSCs) have achieved great attention due to their expressive power conversion efficiency (PCE) up to 25.7%. To improve the photovoltaic performance of PSCs, interface engineering between the perovskite and hole transport layer (HTL) is a widely used strategy. Following this concept, benzyl trimethyl ammonium chlorides (BTACls) are used to modify the wet chemical processed perovskite film in this work. The BTACl‐induced low dimensional perovskite is found to have a bilayer structure, which efficiently decreases the trap density and improves the energy level alignment at the perovskite/HTL interface. As a result, the BTACl‐modified PSCs show an improved PCE compared to the control devices. From device modeling, the reduced charge carrier recombination and promoted charge carrier transfer at the perovskite/HTL interface are the cause of the open‐circuit ( V oc ) and fill factor (FF) improvement, respectively. This study gives a deep understanding for surface modification of perovskite films from a perspective of the morphology and the function of enhancing photovoltaic performance.

Colloidal TiO2-Modified Mesoporous Electron Transport Layer in Perovskite Solar Cells

“…Meanwhile, the JSC is typically determined by the perovskite absorber. The quality of the perovskite film could be influenced by the physical properties of the perovskite crystals, wherein large grains with minimum boundaries are favored [14]- [19]. Despite being less affected than VOC, the ETL variation still shows some effect in the JSC, as also confirmed by the IPCE results.…”

Improved power conversion efficiency and stability of perovskite solar cells induced by dual interface passivation

“…Perovskite solar cells (PSCs) have rapidly advanced in the photovoltaic field, achieving over 26 % power conversion efficiency (PCE) in about twelve years [1] . Unlike traditional silicon or thin-film cells, PSCs offer tunable bandgaps, efficient light absorption, long exciton diffusion lengths, and high charge mobility.…”

Constructing robust heterointerfaces for carrier viaduct via interfacial molecular bridges enables efficient and stable inverted perovskite solar cells

“…35 Therein, quaternary ammonium salts with the formula R 4 N + X (where R is an alkyl or aryl group), such as phenyltrimethylammonium iodide and benzyl trimethyl ammonium chloride (BTACl), have superior thermochemical and moisture stability compared with primary ammonium, due to the elimination of reactive protons by lipophilic alkyl. [36][37][38] They exhibited extraordinary effects on the passivation perovskite surface in different contexts, including 2D perovskite PV devices and OLEDs. 37,39,40 However, the underlying mechanism of the effect of the molecular configuration and intrinsic electronic properties of the bulk quaternary ammonium cations on PTAA interfacial properties and thus the PV performance of PSCs are still unclear.…”

“…[36][37][38] They exhibited extraordinary effects on the passivation perovskite surface in different contexts, including 2D perovskite PV devices and OLEDs. 37,39,40 However, the underlying mechanism of the effect of the molecular configuration and intrinsic electronic properties of the bulk quaternary ammonium cations on PTAA interfacial properties and thus the PV performance of PSCs are still unclear.…”