An international research team has developed a flexible quantum dot solar cell based on all-inorganic cesium-lead iodide (CsPbI3) perovskite.
The researchers built the cell by integrating quantum dots (QDs) with high surface areas into a thin hybrid interfacial architecture (HIA) and by adding phenyl-C61-butyric acid methyl ester (PCBM), which is known as one of the best-performing electron acceptors commonly used in organic photovoltaic devices, into the CsPbI3 quantum dot layer.
“PCBM was added into the CsPbI3 QDs dispersed in chlorobenzene (CB) to obtain a hybrid solution,” the researchers explained. “The CsPbI3 QDs with and without PCBM have a similar cubic shape with an average size of about 10 nm, characterized by the transmission electron microscopy.” The quantum dot solution was spin-coated onto a substrate under ambient conditions with a relative humidity lower than 10% at room temperature.
The PCBM bonds, according to the scientists, create an exciton cascade between the CsPbI3 quantum dot layer and the electron transport layer (ETL) made of Tin(IV) oxide (SnO2). The excitons have the potential to amplify the amount of electricity generated by the photons a solar cell absorbs.
The solar cell reportedly showed a power conversion efficiency of 15.1%, which the scientists said is quite high for CsPbI3 QD solar cells. “More importantly, we also obtained flexible perovskite QD solar cells with a power conversion efficiency of 12.3% assisted by the HIA strategy, as well as improved mechanical flexibility relative to similar thin-film perovskite compositions,” the scientists stated.
he research group includes scientists from the Nankai University and the Soochow University in China, the Macquarie University and the University of New South Wales in Australia. and the US Department of Energy's National Renewable Energy Laboratory.