Noncrystalline Hybrid Lead Halides with Liquid-Polymer Characteristics

Abstract

Hybrid lead halide (HLH) semiconductors, particularly those featuring perovskite and its derivative structures, have been popular materials with many promising optoelectronic applications. In general, HLHs are predominantly crystalline solids, whether they are bulk single crystals, microcrystals, or nanocrystals. This paper shows that when some short-chain Jeffamine, a widely used polyetheramine, is used as the organic species, the resultant HLH would become noncrystalline with unusual liquid-polymer-like characteristics. In this material, Jeffamine ammoniums and lead halide octahedron frameworks are both arranged amorphously, while its optical properties are similar to those of crystalline HLHs. In contrast to conventional organic species, Jeffamine exhibits a disordered molecular packing, which is believed to account for the peculiar characteristics of the HLH products. Through A-site engineering with Jeffamine, even classic lead halide perovskites such as CsPbBr3 can acquire partial noncrystallinity and transform into a liquid-polymer-like form. This discovery demonstrates that Jeffamine as a novel organic species would confer liquid-polymer properties to the products, which may provide a strategy to transform HLH materials and classic halide perovskites into special “liquid semiconductors”, thereby potentially enabling new processing techniques and new designs of soft electronics.

Exceptional optical performance of the zero-dimensional hybrid cuprous halide ETPA2Cu2I4 as an X-ray scintillator

“…The properties of this ionic liquid are similar to those of crystalline metal halides that are now widely reported, including semiconducting properties with exciton self-trapping behaviors, halogen-dependent absorption and emission, with glass transition similar to that of liquid polymers at low temperatures. 32–34 Consequently, they offer stability, low volatility, ease of solution processing, and excellent structural design flexibility. Recent efforts have seen the synthesis of various ion-type cuprous metal halides.…”