WO3:AgInS2 quantum dot electron transport layers in enhanced perovskite solar cells

Abstract

The development of the electron transport layers (ETL) was crucially important for the improvement of charge extraction and transportation in perovskite solar cells (PSCs). Here, dual electron transport layers of TiO2 and WO3 mixed with different sizes of AgInS2 quantum dots (TiO2/WO3:AgInS2 QDs) were fabricated for planar perovskite solar cells. The peak intensity of the photoluminescence (PL) of the synthesized AgInS2 QDs were redshifted from 554 to 655 nm with an increased radius of AgInS2 QDs from 3.82 ± 0.52 to 7.78 ± 1.37 nm. The PL intensity of the perovskite film on TiO2/WO3:AgInS2 QDs was quenched by the addition of AgInS2 QDs. The improved device stability was probably caused by the WO3:AgInS2 QDs layer protecting the interface of perovskite layers from direct contact with TiO2 to prevent UV decomposing. Therefore, the TiO2/WO3:AgInS2 QDs as electron transport layers promoted the perovskite solar cell performance and enhanced the long-term stability. Graphical abstract: [Figure not available: see fulltext.].