Properties of Perovskite Solar Cells with Low Temperature Sintered SnO2 Electron Transport Layers

Abstract

This study investigated the photovoltaic properties and microstructure of perovskite solar cells (PSCs) with an ITO/SnO2/perovskite/HTL/Au electrode configuration, developed with varying sintering temperatures (100~200°C). The goal was to use SnO2 ink as the electron transport layer (ETL) by low-temperature sintering. TGA-DTA analysis was conducted to determine the optimum sintering temperature of the SnO2 ink and the photovoltaic properties were examined by solar simulator analysis. To analyze the microstructure, a 3D profiler, optical microscope, and scanning electron microscopy (SEM) were used. The TGA-DTA analysis results show that SnO2 ink was effectively sintered at the low temperature of 80°C and above. As for the photovoltaic(PV) properties, the PV efficiency was approximately 15% at 120~150°C, and increased to a maximum of 17.16% at 180°C, and then fell to 12% at 200°C. The RMS value, a representation of surface roughness, of the SnO2 layer according to sintering temperature incrementally decreased, reached its lowest at 180°C, before finally increasing. The microstructure analysis showed that the perovskite layer formed on the SnO2 at a sintering temperature of 180°C had a relatively greater grain size of 402 nm and a thickness of 432 nm, thereby improving the PSC’s PV properties. These results suggest it is possible to implement a PCS with SnO2 ETL by low temperature sintering process.

Localized Oxidation Embellishing Strategy Enables High‐Performance Perovskite Solar Cells

“…The improvement of grain size can be to attributed to reduced roughness of the LOE ETL. For several underneath layers, for example, TiO 2 , [27] SnO 2 , [28] ITO [29] and CuSCN, [30] the grain size of grown perovskite film increased with the decrease of surface roughness of underneath layer. We can deduce that rough surface is detrimental to the layer growth since some large clusters may be formed during the deposition.…”