New photoluminescence hybrid perovskites with ultrahigh photoluminescence quantum yield and ultrahigh thermostability temperature up to 600 K

The rapid development of organic-inorganic metal halides in optoelectronic devices has been considered a promising approach for light-emitting diodes. Mn-based halogen hybrids represent a class of fascinating luminescence functional materials. Up to date, studies on Mn-based metal halides remain blurry and suffer from instability and low photoluminescence quantum yield (PL QY). Here, the single crystalline of MEA(MnBr4-xClx)2 (MEA=((CH3)4N)((C2H5)4N)2·NH4, x = 0, 2, 3) were designed and constructed by a one-pot solution method for the first time, featuring brilliant green emissions under ultraviolet light and revealing PL QY up to 99 ± 1% with x = 3 at room temperature. The excellent luminescence is ascribed to the Mn2+ d5 configuration with the 4T1–6A1 transition. Moreover, the thermostability and anomalous photoluminescence (PL) behavior triggered by heat are modulated via varying halogen ratio Cl/Br. Particularly, MEA(MnBr4)2 has an ultrahigh melting up to 600 K, which is, as we know, the highest one among the Mn-based organic-inorganic hybrid compounds. Our findings not only present the outstanding performance of three crystals, but also highlight the potential of these compounds in optoelectronics.