Halogen substitution regulates the phase transition temperature and band gap of semiconductor compounds.

(CH3CH2NH3)3BiX6 and (CH2ClCH2NH3)3BiX6 (X = Cl, Br) obtained by halogen substitution not only realize the adjustment of the phase transition in a relatively wide temperature range, but also optimize the semiconductor performance. This will promote the exploration and construction of semiconductor materials with tunable temperatures and lower band gaps.