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Superlattice period dependence on nonradiative recombination centers in the n-AlGaN layer of UV-B region revealed by below-gap excitation light.
- Source :
-
AIP Advances . Mar2020, Vol. 10 Issue 3, p1-10. 10p. - Publication Year :
- 2020
-
Abstract
- Nonradiative recombination (NRR) centers in n-AlGaN layers of UV-B AlGaN samples with different numbers of superlattice (SL) periods (SLPs), grown on the c-plane sapphire substrate at 1150 °C by the metalorganic chemical vapor deposition technique, have been studied by using below-gap-excitation (BGE) light in photoluminescence (PL) spectroscopy at 30 K. The SLP affects the lattice relaxation of the SL and n-AlGaN layer. The PL intensity decreased by the superposition of BGE light of energies from 0.93 eV to 1.46 eV over the above-gap-excitation light of energy 4.66 eV, which has been explained by a two-level model based on the Shockley–Read–Hall statistics. The degree of PL quenching from n-AlGaN layers of the sample with SLP 100 is lower than those of other samples with SLP 50, 150, and 200. By a qualitative simulation with the dominant BGE energy of 1.27 eV, the density ratio of NRR centers in n-AlGaN layers of 50:100:150:200 SLP samples is obtained as 1.7:1.0:6.5:3.4. This result implies that the number of SLP changes lattice relaxation and determines the density of NRR centers in the n-AlGaN layer, which affects the performance of LEDs. [ABSTRACT FROM AUTHOR]
- Subjects :
- *CHEMICAL vapor deposition
*SAPPHIRES
Subjects
Details
- Language :
- English
- ISSN :
- 21583226
- Volume :
- 10
- Issue :
- 3
- Database :
- Academic Search Index
- Journal :
- AIP Advances
- Publication Type :
- Academic Journal
- Accession number :
- 142494564
- Full Text :
- https://doi.org/10.1063/1.5134698