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Carrier Recombination in Nitride-Based Light-Emitting Devices: Multiphonon Processes, Excited Defects, and Disordered Heterointerfaces

Authors :
Grigorii Savchenko
Evgeniia Shabunina
Anton Chernyakov
Nadezhda Talnishnikh
Anton Ivanov
Alexandr Abramov
Alexander Zakgeim
Vladimir Kuchinskii
Grigorii Sokolovskii
Nikita Averkiev
Natalia Shmidt
Source :
Nanomaterials, Vol 14, Iss 13, p 1072 (2024)
Publication Year :
2024
Publisher :
MDPI AG, 2024.

Abstract

We study recombination processes in nitride LEDs emitting from 270 to 540 nm with EQE ranging from 4% to 70%. We found a significant correlation between the LEDs’ electro-optical properties and the degree of nanomaterial disorder (DND) in quantum wells (QWs) and heterointerfaces. DND depends on the nanoarrangement of domain structure, random alloy fluctuations, and the presence of local regions with disrupted alloy stoichiometry. The decrease in EQE values is attributed to increased DND and excited defect (ED) concentrations, which can exceed those of Shockley–Read–Hall defects. We identify two mechanisms of interaction between EDs and charge carriers that lead to a narrowing or broadening of electroluminescence spectra and increase or decrease EQE, respectively. Both mechanisms involve multiphonon carrier capture and ionization, impacting EQE reduction and efficiency droop. The losses caused by these mechanisms directly affect EQE dependencies on current density and the maximum EQE values for LEDs, regardless of the emission wavelength. Another manifestation of these mechanisms is the reversibility of LED degradation. Recombination processes vary depending on whether QWs are within or outside the space charge region of the p-n junction.

Details

Language :
English
ISSN :
14131072 and 20794991
Volume :
14
Issue :
13
Database :
Directory of Open Access Journals
Journal :
Nanomaterials
Publication Type :
Academic Journal
Accession number :
edsdoj.f7650a2221944f97b1adc82386f51453
Document Type :
article
Full Text :
https://doi.org/10.3390/nano14131072