Dual polarization for efficient III-nitride-based deep ultraviolet micro-LEDs

Zhongqiu Xing; Yongjie Zhou; Aoxiang Zhang; Yipu Qu; Fang Wang; Juin J. Liou; Yuhuai Liu

doi:10.1038/s41598-024-69146-4

Scientific Reports (Aug 2024)

Dual polarization for efficient III-nitride-based deep ultraviolet micro-LEDs

Zhongqiu Xing,
Yongjie Zhou,
Aoxiang Zhang,
Yipu Qu,
Fang Wang,
Juin J. Liou,
Yuhuai Liu

Affiliations

Zhongqiu Xing: National Center for International Joint Research of Electronic Materials and Systems, International Joint-Laboratory of Electronic Materials and Systems of Henan Province, School of Electrical and Information Engineering, Zhengzhou University
Yongjie Zhou: Basic Teaching Department, Zhengzhou University of Railway Engineering
Aoxiang Zhang: National Center for International Joint Research of Electronic Materials and Systems, International Joint-Laboratory of Electronic Materials and Systems of Henan Province, School of Electrical and Information Engineering, Zhengzhou University
Yipu Qu: National Center for International Joint Research of Electronic Materials and Systems, International Joint-Laboratory of Electronic Materials and Systems of Henan Province, School of Electrical and Information Engineering, Zhengzhou University
Fang Wang: National Center for International Joint Research of Electronic Materials and Systems, International Joint-Laboratory of Electronic Materials and Systems of Henan Province, School of Electrical and Information Engineering, Zhengzhou University
Juin J. Liou: School of Electrical and Information Engineering, North Minzu University
Yuhuai Liu: National Center for International Joint Research of Electronic Materials and Systems, International Joint-Laboratory of Electronic Materials and Systems of Henan Province, School of Electrical and Information Engineering, Zhengzhou University

DOI: https://doi.org/10.1038/s41598-024-69146-4
Journal volume & issue: Vol. 14, no. 1
pp. 1 – 10

Abstract

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Abstract The deep ultraviolet (DUV) micro-light emitting diode (μLED) has serious electron leakage and low hole injection efficiency. Meanwhile, with the decrease in the size of the LED chip, the plasma-assisted dry etching process will cause damage to the side wall of the mesa, which will form a carrier leakage channel and produce non-radiative recombination. All of these will reduce the photoelectric performance of μLED. To this end, this study introduces polarized bulk charges into the hole supply layer (p-HSL) and the electron supply layer (n-ESL) respectively (dual-polarized structure) of the DUV μLED at an emission wavelength of 279 nm to enhance the binding of carriers and increase the injection efficiency of carriers. This is because the polarization-induced bulk charge can shield the polarized sheet charge on the interface and reduce the polarization electric field. The reduced polarization electric field in p-HSL can increase the effective barrier height of the conduction band in the p-type region and reduce the effective barrier height of the valence band. The decrease in the polarized electric field of n-HSL can reduce the thermal velocity of electrons, thereby enhancing the electron injection efficiency, reducing the Shockley–Read–Hall (SRH) recombination, and increasing the effective barrier height of the valence band. The study results indicate that the electron concentration and hole concentration of a μLED with dual polarization were increased by 77.93% and 93.6%, respectively. The optical power and maximum external quantum efficiency of μLED reached 31.04 W/cm2 and 2.91% respectively, and the efficiency droop is only 2.06% at 120 A/cm2. These results provide a new approach to solving the problem of insufficient carrier injection and SRH recombination in high-performance DUV μLEDs.

Published in Scientific Reports

ISSN: 2045-2322 (Online)
Publisher: Nature Portfolio
Country of publisher: United Kingdom
LCC subjects: Medicine; Science
Website: https://www.nature.com/srep/

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