Advances in Perovskite Single Crystal Thin Films: Synthesis Methods and Applications in Photodetection

Abstract Halide perovskites have generated tremendous interest for photodetectors (PDs), mainly because of their unique optoelectronic properties, wide wavelength coverage, and facile fabrication process. Perovskite single crystal thin films (SCTFs) characterized by their grain‐boundary‐free structures and thin thickness are expected to enhance the optoelectronic performance and broaden applications of PDs. In this review, the latest progress in perovskite SCTFs is examined, emphasizing main synthesis technologies, strategies for integrating SCTFs within devices, and applications in photodetection. Besides, the classical synthesis methods for perovskite SCTFs are analyzed in detail elucidating the respective advantages and limitations. Moreover, proper integration of perovskite SCTFs into devices is one of the prerequisites for the potential optoelectronic device fabrication, and three main strategies are discussed thoroughly including the transfer of synthesized single crystals for electrode deposition, in situ growth of SCTFs on the electrode/substrate, as well as in situ growth of SCTFs on the transport layer. Along with interface engineering strategies which energized high‐performance SCTF PDs, the applications for high‐performance SCTF PDs including flexible PDs, PD arrays for imaging, and narrowband photodetection are further analyzed. Finally, the future opportunities of perovskite SCTFs are presented, with the expectation of stimulating new ideas and further advances on designs for superior‐performance PDs.