Oscillations in Absorption from InGaN/GaN Quantum Well to Continuum

We analyze theoretically an InGaN/GaN n-i-p diode with a single quantum well supporting only one bound state. The bottom parts of the diode, namely the first barrier and the quantum well, are heavily n-doped with silicon at 5 × 1019 cm−3 to ensure a high electron concentration in the well. The voltage drop in the diode occurs in the second AlGaN barrier, which is undoped, and structure ends with a p-doped GaN. The band structure of the diode is calculated by a Schrodinger–Poisson drift-diffusion solver. Next, we calculate the absorption from the bound state in the well to the “continuum” above the well. We show the oscillatory behavior of the spectrum, with the amplitude decreasing with more negative voltage applied to the diode. Oscillations are due to interferences of the wavefunctions between the edges of the well and the slope of the potential barrier.