Effect of composition disorders on band structure and optical gain spectra of GaInNAs/GaAs quantum wells

Abstract

The effects of non-uniform compositions (the composition disorders) of indium and nitrogen, in a Ga0.59In0.41N 0.038As0.962/GaAs singlequantum well (QW) along the growth direction, on the QW's band structure and further on its optical gain spectrum have been studied theoretically. The 10-band k-p model and the many-body optical gain model have been employed, respectively, to calculate the band structure and the optical gain of the QW. The subband energy dispersions, the optical gains of the transverse electric (TE) and transverse magnetic (TM) modes, and the radiative current densities have been investigated. The composition disorders lead to blueshift in carrier's transition energy, which is mainly due to indium composition disorder while nitrogen composition disorder only plays minor role. The TM mode optical gain is significantly enhanced and the threshold current density is increased in the composition disordered QW structure. These results may provide important supports in the design and fabrications of GaInNAs/GaAs QW based optoelectronic devices. © 2009 The Japan Society of Applied Physics.