Efficient Perovskite Nanocrystal‐Based Optoelectronic Devices

Abstract

Halide perovskites are expected to be widely used in light-emitting diodes (LEDs) due to their excellent optoelectronic properties, such as high luminous efficiency, controllability of luminescence wavelength, and wide color gamut. However, because the exciton binding energy of 3D halide perovskite films is relatively low (%150 meV), various techniques have been applied to increase the exciton binding energy and thereby improve the performance of devices. Among them, 0D halide perovskite nanocrystals (NCs) are widely used because the low-dimensional perovskite effectively confines the excitons in NCs. In particular, perovskite NCs facilitate color tuning with quantum confinement by controlling the size. Herein, it is aimed to provide an overview of various approaches for synthesizing perovskite NCs and post-treatment methods to achieve high-efficiency LEDs.

Air‐Stabilized Lead‐Free Hexagonal Cs3Bi2I9 Nanocrystals for Ultrahigh‐Performance Optical Detection

“…Currently, the synthesis of Cs 3 Bi 2 I 9 perovskite nanocrystals has been carried out mainly by the hot-injection method, where cesium oleate mixed with bismuth halide for a few seconds at elevated temperatures, but pre-synthesis of cesium oleic acid is required and the control of the size is suboptimal. [14][15][16] Moreover, it is generally not easy to realize a broadband response because of its high exciton binding energy, which is detrimental to photocarrier mobility and collection. And also, the Cs 3 Bi 2 I 9 perovskites serving as photodetectors often behave slow carrier mobility and relatively weak responsivity due to the layered vacancy crystal structure, which restricts the corresponding follow-up developments and technical applications.…”

Tiny spots to light the future: advances in synthesis, properties, and application of perovskite nanocrystals in solar cells

“…It is required to remove unreacted precursors and the excess ligands present on the surface, which otherwise can act as trap centers for photogenerated charge carriers. 127 Usually, the purification is performed by redispersing the NC in polar solvents ( e.g. methanol, acetone, or ethyl acetate), known as “poor solvents”, which do not have the ability to solubilize the NC.…”

Anion Exchange in Lead Halide Perovskites: An Overview

“…[55,[61][62][63] Thus, the efficiency of the LEDs made using lead halide perovskites is also high. [55,61,64,65] The anion exchange reactions enabled the facile synthesis of perovskite nanocrystals with desired emission properties very rapidly at a small cost. [66] This has tremendous importance in display devices.…”