Papers by Keyword: QW

Abstract: We have investigated the effect of well growth rate on threshold current and slope efficiency of GaN-based laser diodes (LDs). The lasing performance was significantly dependent on optical and crystal quality of In_0.08Ga_0.92N/ GaN QWs with different well growth rates. The InGaN QWs grown with lower growth rate represented better interface quality and had low surface defects in the InGaN/GaN QW region. In addition, InGaN QWs grown with lower growth rate exhibited the higher optical properties such as the higher PL intensity and the smaller blueshift with increasing excitation power density. The present results suggest that optical and crystal qualities of InGaN/InGaN MQW are significantly improved by lowering well growth rate, resulting in the increase of slope efficiency and the decrease of threshold current density in GaN-based LDs.

Abstract: In this paper, charge control mechanism and carrier features have been precisely investigated in InxGa1-xN/InN/InxGa1-xN based quantum-well double heterostructure high electron mobility transistors (QW-DHEMTs). A study of charge control in the InxGa1-xN/InN/InxGa1-xN structure is performed by self-consistently solving Schrödinger equation in conjunction with Poisson’s equation taking into account the spontaneous and piezoelectric polarization effects. The potential profile and the distribution of electron density in the channel as a function of gate voltage are investigated here. A large conduction band offset of about 2.2eV is obtained for the proposed device for In content x=0.05, which ensure better carrier confinement and higher sheet charge density. The influence of In composition(x) and doping concentration of InxGa1-xN upper barrier on sheet charge density and carrier distributions in channel is also presented. This analysis provides a platform to investigate the InN based QW-DHEMTs and to optimized their design.