Perovskite‐Based Nanocrystals: Perovskite‐Based Nanocrystals: Synthesis and Applications beyond Solar Cells (Small Methods 6/2018)

Abstract

In fact, the reason that these hybrid perovskites receive so much attention is their excellent optoelectronic properties, such as high carrier mobility, long carrier-diffusion length (>100 µm), small exciton binding energy, and strong light-absorp-tion ability in the UV–vis range. [12–25] The rich optoelectronic properties in their bulky state make scientists believe that reducing their sizes to the nanoscale should bring further unprecedented phys-ical phenomena. Perovskite nanocrystals are tiny particles with dimensional varia-tion from several to hundreds of nanometers, and their corre-sponding properties are highly correlated to the sizes, shapes, and crystallographic structures of the as-prepared nanocrys-tals. [26] The first reported synthesis of hybrid perovskite nanocrystals emerged in 2014, where Julia et al. demonstrated how to fabricate 6 nm sized organic–inorganic hybrid perov-skite nanocrystals through a simple and fast method based on the use of an ammonium bromide with a medium-length alkyl chain. [27] In 2015, Kovalenko and co-workers firstly realized the synthesis of all-inorganic perovskite nanocrystals. [28] Since then, different perovskite nanocrystals have been successfully prepared in succession. [29,30] As emerging materials, perovskite nanocrystals have received great attention in a very short time due to their remarkable characteristics including high fluorescence quantum effi-ciency, narrow emission band width, and decent stability. [31,32] Great efforts have been devoted to exploring new synthetic routes, basic material properties, and photophysical behavior. According to the morphologies of the as-obtained perovskite nanocrystals, these nanomaterials can be generally divided into amorphous nanoparticles, nanocubes, nanoplatelets, and nanowires. Because of their diverse morphologies and tun-able optical properties, different optoelectronic applications based on perovskite nanocrystals have sprung up. [32] Except for well-developed perovskite photovoltaics, red/green/blue pero-vskite–based light-emitting diodes have been reported. [32–34] Furthermore, amplified spontaneous emission and lasing based on these nanocrystals have also been realized. [35–37] Here, we will only focus on the recent progress in perovskite nanocrys-tals including synthetic methods and their applications beyond solar cells, since numerous scientific articles related to pero-vskite solar cells have been carefully summarized. Specifically, different synthetic routes to prepare perovskite nanocrystals will be introduced, [38–43] followed by their various applications, including perovskite light-emitting diodes, amplified sponta-neous emission and lasing, photodetectors, resistance random access memory devices, and piezoelectric nanogenerators. The recent progress in perovskite nanocrystals, including synthetic methods and their applications beyond solar cells, is discussed. Specifically, different synthetic routes to prepare various perovskite nanocrystals are considered, followed by their applications, including light-emitting diodes, amplified spontaneous emission and lasing, photodetectors, resistance random access memory devices, and piezoelectric nanogenerators. Finally, an outlook for the future potential applications and possible challenges of perovskite nanocrystals is addressed.