Quantum Confinement Effects in Organic Lead Tribromide Perovskite Nanoparticles

Abstract

The optical and electronic properties of nanoparticles/ nanocrystals (NC) of methylammonium lead tribromide perovskite (MAPbBr3) have been studied in detail. We observe the effect of quantum confinement in particles of an average diameter of ∼6 nm and smaller, in the form of an increase in excitonic nature with decrease in particle size. The differences in the photophysical properties in bulk and NC forms of MAPbBr3 are clearly observed in the temperature dependent measurements, and provide insight into the length scales prevalent in this system. We demonstrate devices consisting of active layers of NC in conjunction with low band gap polymer semiconductors which exhibit the dual functionality of a light emitting diode in the forward bias and a photodetector in the reverse bias.graphic