Spectral function of InAs∕InGaAs quantum dots in a well detector using Green’s function

Theoretical modeling of an InAs∕InGaAs quantum dot-in-a well (DWELL) detector is reported. The DWELL structure consists of pyramidal-shaped InAs quantum dots with dimensions of 11nm (base) and 6.5nm (height) placed on the top half of an InGaAs quantum well of 11nm width, which is buried in a GaAs matrix. The Green’s function method is used to calculate the spectral function and the density of states of the DWELL. The kinetic equation that governs Green’s functions is solved numerically using the method of finite differences. From the information obtained from the density of states, the responsivity of the DWELL can be estimated. The calculated energy eigenvalues are compared with the experimentally measured responsivity of a DWELL detector.