Burstein-Moss shift of lead halide perovskite quantum dots induced by electron injection from graphene oxide

Highlights: • The optical property of CsPbX₃ QDs is extremely sensitive to the electron injection. • One electron in a 10 nm-sized QD will bring forth an electron density of ~10¹⁸ cm⁻³. • It is the first time to observe B-M effect arisin from electron transfer. As an ultrathin transport layer, graphene-based materials play an increasingly important role in perovskite optoelectronics. Full comprehension of the carrier transfer process between them is of great significance, however, seldom attention has been paid to how the carrier transfer, from graphene derivative to perovskite, affects the physical property of perovskite. Here, we report that CsPbBr₃ and CsPbI₃ QDs produce a Burstein-Moss type photoluminescence (PL) blueshift arisen from the electron transfer from graphene oxide (GO), and in CsPbI₃ QDs this effect is highly notable, ~50 meV. Such results indicate that perovskite QDs is highly optically sensitive to the electron injection, and quite promising in optoelectronic modulator applications.