Lead-Free Organic Manganese (II) Bromide Hybrid with Highly Efficient and Stable Green Emission for UV Photodetection

Lead halide perovskites have been widely used in optoelectronic devices due to their excellent properties; however, the toxicity of lead and the poor stability of these perovskites hinder their further application. Herein, we report a zero-dimensional (0D) lead-free organic manganese (II) bromide hybrid compound of (TBA)2MnBr4 (TBA+ = tetrabutylammonium cation) single crystals (SCs) with great environmental stability. The (TBA)2MnBr4 SCs show a strong green emission peak at 518 nm with a high photoluminescence quantum yield (PLQY) of 84.98% at room temperature, which is attributed to the d-d transition of single Mn2+ ions, as also confirmed through density functional calculation. A green light-emitting diode was produced based on (TBA)2MnBr4 SCs, which exhibited CIE coordinates (0.17, 0.69) close to those of standard green. A photodetector fabricated by the (TBA)2MnBr4 SCs shows an obvious photo response with a rapid millisecond rise/decay response time (at 365 nm). Our findings promote the research of Mn(II)-based organic–inorganic hybrid materials and pave the way by using these materials for future high-performance optoelectronic devices.