Centimeter-Size Square 2D Layered Pb-Free Hybrid Perovskite Single Crystal (CH3NH3)2MnCl4 for Red Photoluminescence

Due to its excellent luminescent properties, such as high stability, narrow band emission, strong luminescence, etc., hybrid organic-inorganic lead perovskites have great potential for application in optoelectronic devices. Compared to their conventional (3D) structure counterparts, (2D) structure perovskite exhibit enhanced moisture stability. Moreover, with the enhancement of exciton binding energy and limitation of charge carriers, 2D layered structure perovskite is considered ideal candidate materials for efficient light-emitting diode (LED). However, disappointing characteristics of Pb toxicity in hybrid organic-inorganic lead perovskites, which is considered as the biggest hidden danger to cause environmental pollution and health damage in further large-scale applications. Thus, exploiting the impressive properties and practical uses of 2D layered structure Pb-free hybrid organic-inorganic perovskites in LED fields is deemed as urgently needed. In our work, the centimeter-size square 2D layered Pb-Free (CH3NH3)2MnCl4 single crystal was grown successfully with diverse crystal morphology, from two different solutions. The material can be excited by light in different wavelength bands. The main peak of the emission spectrum located at 608 nm and the full width at half maximum (FWHM) is 72 nm. And in further, we reported that the LED prepared by (CH3NH3)2MnCl4 single crystal, with good luminous, can emit obvious red light with QE of 2.4% @417 nm excited and can be used for white light illumination.