Intraband absorption of D− center in CdSe/CdS/CdSe/CdS multilayer quantum dot

Absorption characteristics of a D− center in CdSe/CdS/CdSe/CdS multilayer quantum dot are studied within the framework of effective mass approximation. The energy eigen values and corresponding wave functions are obtained by solving the coupled Poisson-Schrondinger equations self-consistently, using finite difference matrix diagonalization method. Based on this, the effect of core radius, shell thickness and well width on absorption coefficient and absorption wavelength are investigated. This model predicts that, the D− center has considerable intraband absorption, of the order of 103cm−1, in the far infrared region. The absorption characteristics can be finely tuned by varying the layer thicknesses.