Recent advances and prospects toward blue perovskite materials and light‐emitting diodes

Abstract

Perovskite based light‐emitting diodes (PeLEDs) have become a powerful candidate for next‐generation solid‐state lightings and high‐definition displays due to their high photoluminescence quantum yield (PLQY), tunable emission wavelength over the visible spectrum, and narrow emission linewidths. Over the past few years, the development of red‐ and green‐emissive PeLEDs has rapidly increased, and the corresponding external quantum efficiencies (EQE) have exceeded 20%. However, the research progress of blue‐emitting PeLEDs is limited by its poor material quality and inappropriate device structure. Currently, the maximum EQE of blue PeLED is only 6.2%, which is far from the industrialization requirements. In order to promote the development of blue PeLEDs, we summarize the recent research progress of blue perovskite materials and LEDs and discuss several fatal challenges, mainly embodied in low efficiency and poor stability. In order to overcome these challenges, detailed analysis and strategies are put forward in terms of the materials and devices. For the former, we summarize the feasible strategy for the preparation of efficient and stable blue‐emissive perovskites using component engineering. For the latter, we analyze the advantages and limitations of the different strategies for blue‐emissive perovskite in LEDs. At the end of the review, a comprehensive outlook is detailed, including future development directions and several technical problems to be solved. Thus, we aim to highlight the significance and promote the industrialization of PeLEDs.

In Situ Formed Gradient Bandgap‐Tunable Perovskite for Ultrahigh‐Speed Color/Spectrum‐Sensitive Photodetectors via Electron‐Donor Control

“…Hybrid organic–inorganic perovskites, an extraordinary absorber family with ABX 3 structure, not only possess bandgap‐tunable ability, but also have a series of outstanding photoelectrical properties such as high carrier mobility and small exciton binding energy 20. By adjusting the element of X site, the photoabsorption range of the perovskites can evolve from ultraviolet to near‐infrared 9,11,21. In spite of the great improvement of responsivity, the response speed is still lag behind for the self‐powered perovskite‐based photodetector.…”

Ultrathin PEDOT:PSS Enables Colorful and Efficient Perovskite Light‐Emitting Diodes

“…Metal halide perovskite light‐emitting diodes (Pero‐LEDs) have attracted a great deal of interest in recent years due to their huge potential and promising applications in lighting and future‐generation displays. [ 1–5 ] Their superior optoelectronic properties include high photoluminescence quantum yield (PLQY), [ 6 ] narrow emission bandwidth, broadly tunable band gaps, low raw materials cost, and simple solution‐based fabrication process. [ 7–10 ] Since the first report of room temperature operable Pero‐LEDs in 2014, [ 3 ] this field has undergone an amazing and rapid growth of device performance.…”

Highly Efficient Blue‐Emitting CsPbBr3 Perovskite Nanocrystals through Neodymium Doping

“…[10] One promising solution to addressing these challenges is to fully or partially replace Pb 2+ ions by B-site dopants. [11,12] The doping ions do not only reduce lead toxicity but can also enhance both thermal and phase stability of CsPbX 3 NCs by approaching an optimized Goldschmidt's tolerance factor. [13] B-site cations also play a critical role in determining the electronic band structure of perovskites and consequently their emission properties.…”