Perovskite‐Gallium Nitride Tandem Light‐Emitting Diodes with Improved Luminance and Color Tunability

Abstract

Tandem structures with different subpixels are promising for perovskite‐based multicolor electroluminescence (EL) devices in ultra‐high‐resolution full‐color displays; however, realizing excellent luminance‐ and color‐independent tunability considering the low brightness and stability of blue perovskite light‐emitting diodes (PeLEDs) remains a challenge. Herein, a bright and stable blue gallium nitride (GaN) LED is utilized for vertical integration with a green MAPbBr 3 PeLED, successfully achieving a Pe‐GaN tandem LED with independently tunable luminance and color. The electronic and photonic co‐excitation (EPCE) effect is found to suppress the radiative recombination and current injection of PeLEDs, leading to degraded luminance and current efficiency under direct current modulation. Accordingly, the pulse‐width modulation is introduced to the tandem device with a negligible EPCE effect, and the average hybrid current efficiency is significantly improved by 139.5%, finally achieving a record tunable luminance (average tuning range of 16631 cd m −2 at an arbitrary color from blue to green) for perovskite‐based multi‐color LEDs. The reported excellent independent tunability can be the starting point for perovskite‐based multicolor EL devices, enabling the combination with matured semiconductor technologies to facilitate their commercialization in advanced display applications with ultra‐high resolution.

The Structural and Optical Investigation of Grown GaN Film on Porous Silicon Substrate Prepared by PLD

“…Nowadays, Gallium Nitride (GaN) is one of the III-V nitride semiconductor materials with a hexagonal wurtzite structure that has unique optical properties with a wide tunable direct band-gap of 3.4 eV [1][2][3]. This makes it possible to make optoelectronic devices that work with UV and visible light, like LEDs, LDs, photodiodes, and UV detectors [4][5][6]. Furthermore, GaN has high-rise electron mobility, chemical stability, and great luminescence efficiency [7].…”

The influence of Fermi level position at the GaN surface on carrier transfer across the MAPbI3/GaN interface

“…It brought a breakthrough in solid state lighting 3 and established a whole branch of high-power electronics. 4 Nowadays, it also successfully acts as a reliable platform for tandem devices taking on board emerging materials such as van der Waals crystals and perovskites, which results in the demonstration of solar cells, 5 LEDs, 6,7 transistors 8 and photodetectors. 9,10 All presently proposed optoelectronic devices are multilayered, based on heterostructures with multiple interfaces.…”

High-performance perovskite light-emitting diodes based on grain boundary passivation: progress, challenges and perspectives

“…Metal halide perovskites with the chemical structure of ABX 3 have attracted attention owing to their excellent optoelectrical properties, such as tunable emission wavelength, narrow full width at half-maximum (FWHM), long carrier diffusion length, high color purity and wide color gamut. [1][2][3][4][5] Generally, A is a monovalent organic or inorganic cation, B is a divalent metallic cation, and X is a halide anion (e.g., A: Cs + , CH 3 NH 3 + (MA + ), CH(NH 2 ) 2 + (FA + ); B: Pb 2+ , Sn 2+ ; X: Cl À , Br À , I À ). 2,6,7 Since the first report of solution-processed PeLEDs that operated at room temperature in 2014, 8 various types of strategies, i.e., additive engineering, interface engineering, composition engineering and so on, have been carried out to improve the performance and stability of PeLEDs.…”

“…Metal halide perovskites with the chemical structure of ABX 3 have attracted attention owing to their excellent optoelectrical properties, such as tunable emission wavelength, narrow full width at half-maximum (FWHM), long carrier diffusion length, high color purity and wide color gamut. 1–5 Generally, A is a monovalent organic or inorganic cation, B is a divalent metallic cation, and X is a halide anion ( e.g. , A: Cs + , CH 3 NH 3 + (MA + ), CH(NH 2 ) 2 + (FA + ); B: Pb 2+ , Sn 2+ ; X: Cl − , Br − , I − ).…”