Metal Doping/Alloying of Cesium Lead Halide Perovskite Nanocrystals and their Applications in Light‐Emitting Diodes with Enhanced Efficiency and Stability

Abstract

Metal halide perovskite nanocrystals (NCs) have demonstrated great advances for light‐emitting diodes (LEDs) applications, owing to their excellent optical, electrical properties and cost‐effective solution‐processing potentials. Tremendous progress has been made in perovskite NCs‐based LEDs during the past several years, with the external quantum efficiency (EQE) boosted to over 20 %. Recently, metal doping/alloying strategy has been explored to finely tune the optoelectronic properties and enhance material stability of perovskite NCs, leading to further improved device efficiency and stability of the obtained perovskite NCs‐based LEDs. In this review, we summarize recent progress on the metal doping/alloying of perovskite NCs and their applications in LEDs. We focus on the effects of different metal doping strategies on the structural and optoelectronic properties of the perovskite NCs. In addition, several works on high‐performance LEDs based on metal doped/alloyed perovskite NCs with different light emission colours are highlighted. Finally, we present an outlook on employing metal doping/alloying strategies to further improve the device efficiency and stability of LEDs based on perovskite NCs.

Lead‐Free Halide Double Perovskite Nanocrystals for Light‐Emitting Applications: Strategies for Boosting Efficiency and Stability

“…To boost or modulate photoelectric properties of lead‐free HDP nanocrystals, the metal doping/alloying strategies are widely employed. [ 143–145 ] According to the substitution possibilities of the elements existed in the A 2 B + B 3+ X 6 , A 2 B 4+ X 6 , and A 4 B 2+ B 3+ 2 X 12 HDP structure, we simply classify metal doping/alloying strategies of HDP nanocrystals reported in the literature into the isovalent “B + ‐site”, “B 2+ ‐site”, “B 3+ ‐ site”, and “B 4+ ‐ site” doping/alloying and heterovalent B‐site doping/alloying. The different valence states of B‐site metals in HDP structure provide more possibility of doping/alloying, generating fascinating photoelectricity performance for desired HDP materials.…”

Emergence of Impurity-Doped Nanocrystal Light-Emitting Diodes

“…One of the critical reasons for this phenomenon may be the fact that the emission mechanism becomes complicated if phonon participation is considered [ 57 ]. Therefore, following the previous impurity-doped nanocrystal LEDs [ 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 ], we do not consider phonon participation. Additionally, it is still somewhat controversial for the mechanism of charge-phonon interactions.…”

“…In the case of LEDs, impurity-doped nanocrystals have been extensively explored as versatile emitters. In general, impurity-doped nanocrystal LEDs can emit not only band-edge emissions but also impurity-related emissions [ 66 , 67 , 68 ]. As a consequence, three emission phenomena exist in impurity-doped nanocrystal LEDs (i.e., LEDs exhibit only host emissions, LEDs show only impurity emissions, and LEDs possess both host and dopant emissions).…”

Colloidal quantum dot hybrids: an emerging class of materials for ambient lighting

“…1,2 QDs are promising semiconductor nanocrystals with several unique physical and chemical properties, such as outstanding bang-gap tunability, high photoluminescence quantum yield (PLQY), narrow linewidth and well solution processability. [3][4][5][6][7] These properties of QDs have motivated increasingly intensive research aimed at applying them in the next generation of optoelectronics, including light-emitting diodes (LEDs) [8][9][10] , solar cells [11][12][13][14][15][16] , photodetectors 15,17 , and field-effect transistors 11,18,19 . In fact, with high colour purity and wide colour gamut, televisions, monitors and tablets containing QDs have already appeared and are beginning to thrive in the consumer market.…”