Abstract
Layered metal halide perovskites have attracted enormous research attention over the last few years, befitting their unique optical and electronic properties. Low-dimensional layered perovskites demonstrate great potential for various optoelectronic and sensing applications beyond photovoltaics. Herein, the recent progress and opportunities in 2D and quasi-2D perovskites for light-emitting diodes (LEDs), lasers, memristors, neuromorphic/synaptic applications, UV–vis photodetection, X-ray detection, scintillators, and photocatalytic applications are reviewed. First, the crystal structure, characteristics, and fundamental properties of 2D layered perovskites are discussed. Recent efforts and developments of 2D and quasi-2D metal halide perovskite for light-emitting applications with excellent luminescence properties are reviewed. Unique properties of 2D perovskites, such as negligible leakage current due to restricted carrier transport, high stability, and hydrophobicity, make them viable for memristor devices. After discussing the memristor and neuromorphic devices using 2D perovskites, the outstanding performance of 2D perovskites in UV–vis photodetection including polarization-sensitive photodetection is discussed. 2D perovskites recently proved as a superior candidate in X-ray detection with high stability. Further, the scintillation properties of 2D perovskites for the detection of ionizing radiation are discussed. Finally, some of the very recent achievements and present future outlook, including exciting opportunities in this burgeoning field are highlighted.