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

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 TiO 2 and WO 3 mixed with different sizes of AgInS 2 quantum dots (TiO 2 /WO 3 :AgInS 2 QDs) were fabricated for planar perovskite solar cells. The peak intensity of the photoluminescence (PL) of the synthesized AgInS 2 QDs were redshifted from 554 to 655 nm with an increased radius of AgInS 2 QDs from 3.82 ± 0.52 to 7.78 ± 1.37 nm. The PL intensity of the perovskite film on TiO 2 /WO 3 :AgInS 2 QDs was quenched by the addition of AgInS 2 QDs. The improved device stability was probably caused by the WO 3 :AgInS 2 QDs layer protecting the interface of perovskite layers from direct contact with TiO 2 to prevent UV decomposing. Therefore, the TiO 2 /WO 3 :AgInS 2 QDs as electron transport layers promoted the perovskite solar cell performance and enhanced the long-term stability. Graphical abstract