Retrograde solubility of formamidinium and methylammonium lead halide perovskites enabling rapid single crystal growth

Abstract

Here we show the retrograde solubility of various hybrid perovskites through the correct choice of solvent(s) and report their solubility curves. Retrograde solubility enables to develop inverse temperature crystallization of FAPbX3 (FA = HC(NH2)2(+), X = Br(-)/I(-)). FAPbI3 crystals exhibit a 1.4 eV bandgap--considerably narrower than their polycrystalline counterparts.

Progress in organic-inorganic hybrid halide perovskite single crystal: growth techniques and applications

“…Bakr's [51] group found that the retrograde behavior and ITC were not limited to MAPbX3 perovskites but could be generalized to FAPbX3 by proper solvent selection. For ITC of FAPbI3, 0.8 mol L −1 GBL solution was used to increase the onset of crystallization temperature to 115°C.…”

“…ITC method, initially proposed by Bakr et al [50,51], is based on the unnormal solubility of organic-inorganic hybrid halide perovskite in specific organic solvents. In this method, crystallization is induced by the inverse solubility dependent on temperature in some organic solvents and the overall growth occurs within several hours, which is much faster than that in STL method.…”

Solution-processed visible-blind UV-A photodetectors based on CH3NH3PbCl3 perovskite thin films

“…31 As reported previously, lower trap densities, due to higher dimensional structurally coherent units that are tight in the single crystal compared to their polycrystalline counterparts, result in the narrower band gap and the elimination of excitonic peak. 45,46 The steady-state PL spectra of the four CH3NH3PbCl3 thin films, however, show the shift of emission peaks and different tail lengths. The PL peak blue-shifted from 414.5 nm to 412.5 nm to 411.5 nm when the PbCl2 concentration was increased from 250 mg/mL to 300 mg/mL to 350 mg/mL.…”

Metal Halide Perovskite Single Crystals: From Growth Process to Application

“…Additionally, the ITC method meets the requirements of FAPbX 3 single crystals. Bakr's group reported the retrograde solubility of FA-based perovskites and grew high-quality crack-free FAPbI 3 and FAPbBr 3 single crystals (Figure 2h,i) [75]. By improving the onset of crystallization temperature, they obtained grain boundary-free FAPbI 3 crystals within 3 h. Yang's group obtained 5-mm-sized FAPbI 3 single crystals for the first time via a modified ITC method [74].…”