Time-resolved study of the illumination induced diffusion of ions in bio-inspired hybrid organic-inorganic perovskite MAPbBr3

Hybrid organic-inorganic perovskites have drawn much attention over the last decade due to their high conversion efficiency. Their drawback is that they are not environmentally stable. We have shown that by a bio-inspired method of incorporating amino acids into the lattice of these semiconductors we not only tune the band gap but also increase their stability. As a next stage we want to study the effect the incorporated amino acids have on the known diffusion of Cl- and I- ions in the lattice of MAPbBr3 in which one obtains intermixing, i.e., MAPbBrnX3-n (X = Cl, I, n = 0-3). The diffusion is strongly affected by illumination: intermixed crystals tend to segregate under illumination to Br-rich and X-rich perovskite domains and re-mix when the illumination is turned off. In this propsoal we will study time-resolved diffusion of Lys-incoporated MAPbBrnX3-n when illumination is turned on and then off at various temperatures. We will deduce the diffusion kinetics and activation energy.