Dependence on well widths of total optical absorption coefficient of asymmetric triple GaAlAs/GaAs and GaInAs/GaAs quantum wells

Abstract

Herein, the total optical absorption coefficient (TOAC) and the electronic characteristics of asymmetric triple Ga[Formula: see text]Al[Formula: see text]As/GaAs (A model) and Ga[Formula: see text]In[Formula: see text]As/GaAs (B model) quantum wells (QWs) have been examined related to the well widths (WWs). For TOAC, we first varied all WWs equally, and then we kept a WW constant and changed the other two WWs. The wavefunctions (WFs), the subband energies and the probability densities of asymmetric triple quantum wells (ATQW) with different QW shapes under effective mass approach were determined by the solution of Schrödinger equation. According to the results obtained, the major diversities of A and B models are the effective mass and the energy gap. The potential depth and the energy levels (ELs) of A model are continuously smaller than of B model. We see that WWs have a great influence on TOAC and the electronic features of ATQW. The inter-subband absorption spectrum designates blue/red shifts, when the energy spacing varies with WWs. These characteristics draw a convenient attention for the purpose of adjustable semiconductor devices. Hence, the alteration of this absorption spectrum, which could be fit for many optical modulators and infra-red optical device applications, may be efficiently realized by changing WWs. Highlights Energy spacing varies by increasing WWs. Due to the shape of the wells, the influence of each WW is quite different from the others. TOAC varies with rising WWs. The absorption spectrum illustrates red or blue shifts depending on WWs.