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Manipulating the Trade‐off Between Quantum Yield and Electrical Conductivity for High‐Brightness Quasi‐2D Perovskite Light‐Emitting Diodes
Author(s) -
Wang Zhibin,
Wang Fuzhi,
Sun Wenda,
Ni Ruihao,
Hu Siqian,
Liu Jiyan,
Zhang Bing,
Alsaed Ahmed,
Hayat Tasawar,
Tan Zhan'ao
Publication year - 2018
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201804187
Subject(s) - perovskite (structure) , materials science , optoelectronics , quantum yield , light emitting diode , photoluminescence , diode , luminescence , chemical engineering , optics , physics , engineering , fluorescence
Quasi‐two‐dimensional (quasi‐2D) perovskites are attracting much attention due to their impressive luminescence properties. However, the introduction of insulating bulky cations reduces the charge transport property of mixed‐dimensional perovskites and leads to lowered brightness and increased turn‐on voltage. The trade‐off between high photoluminescence quantum yield (PLQY) and electrical conductivity should be well manipulated to obtain high‐performance perovskite light‐emitting diodes (PeLEDs). Herein, quasi‐2D perovskite BA 2 (CsPbBr 3 ) n‐1 PbBr 4 ‐PEO with high PLQY and excellent carrier injection efficiency is demonstrated by incorporating bulky n ‐butylammonium bromide (BABr), CsPbBr 3 , and polyethylene oxide (PEO). BA can intercalate into the three‐dimensional perovskite framework to form a layered (quasi‐2D) perovskite structure. The ion conductive polymer PEO is used to protect quasi‐2D perovskite crystals. Additional BABr is removed by using anhydrous isopropyl alcohol as a washing agent due to its selective dissolubility. By carefully modulating the optical and electrical properties of quasi‐2D perovskite films, the maximum luminance of PeLEDs is dramatically enhanced from 191 to 33533 cd m −2 , which is the brightest green quasi‐2D PeLED reported thus far, leading to an increase in external quantum efficiency from 1.81% to 8.42%. This work provides a promising route to control the optical and electrical properties of quasi‐2D perovskite films for high‐performance optoelectronic devices.