Two-Dimensional Perovskites and Their Applications on Optoelectronic Devices

Two-dimensional (2D) perovskites have become a research hotspot as one kind of high-performance optoelectronic devices, attracting a great deal of attention in recent years due to their unique structures and interesting optoelectronic properties. Besides the solution-processable, fiexible and wearable characteristics similar to the conventional 2D materials, these new 2D materials can be assembled into uniform and fiexible ultrathin films with highly oriented microstructures. Also, they have a long charge carrier diffusion lengths, low binding energy, high quantum yield, high crystallinity, broad absorption spectra, high light absorption coefficients, low rates of non-radiative charge recombination inherited from three dimensional perovskites. In this review, we focus on the composition characteristics, structural formation rules, photoelectric properties and nonlinear optical properties of two-dimensional perovskites. Specifically, we classify the preparation methods of two-dimensional perovskites into two main types of the solution method and vapor method. Furthermore, we comprehensively summarize the recent advancements of two-dimensional perovskites in the applications of solar cells, photodetectors, light-emitting diodes, field effect transistors and lasers.We also discuss the current challenges and future research directions to achieve optimal performance for practical applications in detail to provide applicable suggestions in designing high-performance two dimensional perovskites for advanced optoelectronic devices in the future.