Electrical and Optical Properties of Crystals with “nipi‐Superstructure”

Abstract

Abstract The zigzag‐shaped potontial in crystals with “nipi‐Superstructure” (a periodic array of n‐ and p‐doped layers, separated from each other by zones of the intrinsic material) splits the bands into subbands. As a consequence the electronic properties as a function of photon frequency or of external fields should show oscillations reflecting the subband structure. Furthermore these crystals should show interesting features, which are based on the weak interaction between carriers of different impurity layers, and on the change of the amplitude of the superstructure potential with the degree of excitation. Thus, the absorption coefficient, as well as the recombination radiation shows a strong red shift, which depends on the degree of excitation. The efficiency for light storage is high. The application of external fields has drastic effects on the absorption coefficient and on the intensity and frequency of luminescence. At high fields electroluminescence with high efficeincy eventually may be observed.