An Organic–Inorganic Perovskitoid with Zwitterion Cysteamine Linker and its Crystal–Crystal Transformation to Ruddlesden‐Popper Phase
Prachi Kour, Mallu Chenna Reddy, Shiv Pal, Siraj Sidhik, Tisita Das, Padmini Pandey, Shatabdi Porel Mukherjee, Sudip Chakraborty, Aditya D. Mohite, Satishchandra Ogale
Abstract
Abstract We demonstrate synthesis of a new low‐D hybrid perovskitoid (a perovskite‐like hybrid halide structure, yellow crystals, P 21/ n space group) using zwitterion cysteamine (2‐aminoethanethiol) linker, and its remarkable molecular diffusion‐controlled crystal‐to‐crystal transformation to Ruddlesden‐Popper phase (Red crystals, Pnma space group). Our stable intermediate perovskitoid distinctly differs from all previous reports by way of a unique staggered arrangement of holes in the puckered 2D configuration with a face‐sharing connection between the corrugated‐1D double chains. The PL intensity for the yellow phase is 5 orders higher as compared to the red phase and the corresponding average lifetime is also fairly long (143 ns). First principles DFT calculations conform very well with the experimental band gap data. We demonstrate applicability of the new perovskitoid yellow phase as an excellent active layer in a self‐powered photodetector and for selective detection of Ni 2+ via On‐Off‐On photoluminescence (PL) based on its composite with few‐layer black phosphorous.