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.