Optical Properties of Perovskite-Organic Multiple Quantum Wells.

A comprehensive study of the optical properties of CsPbBr 3 perovskite multiple quantum wells (MQW) with organic barrier layers is presented. Quantum confinement is observed by a blue-shift in absorption and emission spectra with decreasing well width and agrees well with simulations of the confinement energies. A large increase of emission intensity with thinner layers is observed, with a photoluminescence quantum yield up to 32 times higher than that of bulk layers. Amplified spontaneous emission (ASE) measurements show very low thresholds down to 7.3 µJ cm -2 for a perovskite thickness of 8.7 nm, significantly lower than previously observed for CsPbBr 3 thin-films. With their increased photoluminescence efficiency and low ASE thresholds, MQW structures with CsPbBr 3 are excellent candidates for high-efficiency perovskite-based LEDs and lasers.