Electroluminescence of graded-gap structures with blocking and ohmic contacts

Special features of the electroluminescence of uniformly doped graded-gap structures with blocking and ohmic contacts are studied theoretically. Analytical expressions for the spectral and integrated electroluminescence intensities are derived and analyzed in the case of a constant gradient of the band gap and a strong absorption of light. It is shown that the presence of the blocking contact on the wide-gap face of the graded-gap structure leads to an increase in the efficiency of the negative and, especially, positive electroluminescence compared to the case of a graded-gap structure with two ohmic contacts. The recombination radiation of a graded-gap structure with the blocking contact at the narrow-gap face features in the majority of cases a sign-alternating spectral dependence; a broad band of negative electroluminescence is prevalent in this dependence in the region of high currents. absorption.