2D Perovskite Single Crystals for Photodetectors: From Macro‐ to Microscale

Abstract

Lead‐halide‐based perovskite single crystals have attracted wide attention due to their excellent optical characteristics, photoelectric performance, and designable structures. 2D sheet‐like single‐crystal perovskite materials have several attractive characteristics, including larger exposed facets, adjustable thickness, good light absorption/transparency, and so on. However, single‐crystal perovskite sheets with a thinner thickness (<10 μm) are hard to obtain by conventional mechanical cutting due to the fragility of perovskite single crystals. Herein, the recent progress in research on 2D perovskite single crystals from macro‐ to microscale is reviewed. Crystal growth methods are classified into six strategies, including space‐limit method, surface‐tension method, top‐down method, spin‐coating method, solution‐phase method, and vapor‐phase method. Subsequently, the properties of 2D perovskite single crystals are further highlighted, such as optical properties, crystal defects, carrier transport properties, detection capability, and stability. Moreover, their applications in single‐crystal photodetectors are summarized. Finally, the summary and perspective on 2D perovskite single crystals are also briefly addressed.

Recent progress in waveguide-integrated photodetectors based on 2D materials for infrared detection

“…Unlike the traditional preparation method of 2D materials, perovskites are synthesized by space-limit, surface-tension, and spin-coating methods. Perovskite nanosheets with nano thickness have been applied in photodetectors [132][133][134].…”

High-Quality Solution-Processed Quasi-2D Perovskite for Low-Threshold Lasers

“…Perovskites have attracted widespread interest in developing light-emitting diodes (LEDs) and lasers, thanks to exceptional optoelectronic properties and low fabrication costs. − Higher efficiency lasers with a lower threshold have been a constant goal in the development of lasers. , Organic–inorganic lead halide quasi-two-dimensional (quasi-2D) perovskites are promising gain media for lasing applications because of their high gain, wavelength tunability, and solution processability . Compared with conventional three-dimensional (3D) perovskites, quasi-2D Ruddlesden–Popper perovskites (RPPs) are more environmentally stable. − Moreover, RPPs have a distinct multiple quantum well structure, a high exciton binding energy, and a high photoluminescence quantum yield (PLQY). − The quality of perovskite films is crucial for developing high-performance optoelectronic devices, and dense grains that can form smooth, pinhole-free, and highly crystalline films on the substrate are commonly preferred. , Spin coating is the most widely used and important method to manufacture perovskite devices . The study of crystallization kinetics is very helpful in achieving the best performance of the device.…”

“…17,18 Spin coating is the most widely used and important method to manufacture perovskite devices. 19 The study of crystallization kinetics is very helpful in achieving the best performance of the device. To fabricate high-quality perovskite films, the volatilization of the solvent and the crystallization of the perovskite should be carefully controlled.…”

Single-crystal MAPbI3 microwire arrays by a bilayer flexible interface confinement method for photodetectors

“…13 To address this issue, the design and development of large-size high-quality perovskite single crystal-based devices provides another technology due to their advantages, such as the absence of grain boundaries, few defects, reduced trap state density, high carrier mobility, long carrier transmission distance, and enhanced stability. [14][15][16][17][18] Perovskite single crystals have shown great promise in a wide range of applications in recent years, especially one-dimensional MAPbX 3 (MA + = CH 3 NH 3 + ) single-crystal micro/nanowires. Their distinct geometric structures can not only facilitate efficient carrier transport due to the reduced dimensionality, but also tolerate bending along the perpendicular to form flexible and integrated devices.…”