Investigation of performance characteristics of an Al0.8Ga0.2N-delta-GaN QW laser considering structural parameters

Abstract

We have designed Al0.8Ga0.2N-delta-GaN Quantum Well (QW) Laser to investigate the performance characteristics of device like square momentum matrix element at zone center, spontaneous emission rate and optical gain, with structural parameters like delta width, well width, barrier width and injection carrier density. A Self Consistent model using 6-band k.p method incorporating strain effect due to lattice mismatch, valence band mixing effect, carrier screening effect and both spontaneous and piezoelectric polarization effect has been adopted to calculate the electronic properties of the structure. With the variation of the structural parameters, the detail illustration of the variations of the device characteristics are demonstrated in this work. From the investigation, it has been found that the structure shows a maximum optical output of 6636.8 cm-1 at 425nm emission wavelength for 7A delta width, 12A well width, 60A barrier width and 5×1019 cm-3 carrier density at 300K. Detail relationship between the performance parameters of the structure has been elaborated in this work to obtain the conditions for maximum output of the structure. The calculated device properties are compared favourably with the values reported previously in the literature.