Author(s): Liang, F (Liang, Feng); Zhao, DG (Zhao, Degang); Liu, ZS (Liu, Zongshun); Chen, P (Chen, Ping); Yang, J (Yang, Jing)

Source: OPTICS EXPRESS Volume: 30 Issue: 6 Pages: 9913-9923 DOI: 10.1364/OE.453611 Published: MAR 14 2022

Abstract: An asymmetric multiple quantum well (MQW) without the first quantum barrier layer is designed, and its effect on the device performance of GaN-based blue LDs has been studied experimentally and theoretically. It is found that compared with LD using symmetrical multiple quantum well, device performance is improved significantly by using asymmetric MQW, i.e. having a smaller threshold current density, a higher output optical power and a larger slope efficiency. The threshold current density decreases from 1.28 kA/cm(2) to 0.86 kA/cm(2), meanwhile, the optical power increases from 1.77 W to 2.52 W, and the slope efficiency increases from 1.15 W/A to 1.49 W/A. The electroluminescence characteristics below the threshold current demonstrate that asymmetric MQW is more homogeneous due to the suppressed strain and piezoelectric field. Furthermore, theoretical calculation demonstrates that the enhancement of electron injection ratio and reduction in optical loss are another reason for the improvement of device performance, which is attributed to a smaller electron potential barrier and a more concentrated optical field distribution in the asymmetric structure, respectively. The new structure design with asymmetric MQW is concise for epitaxial growth, and it would also be a good possible choice for GaN-based LDs with other lasing wavelengths. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Accession Number: WOS:000768611900129

PubMed ID: 35299404

ISSN: 1094-4087

Full Text: https://opg.optica.org/oe/fulltext.cfm?uri=oe-30-6-9913&id=470230