Influence of backlighting on current-voltage characteristics of InGaN / GaN-based structures with back-shift

Abstract

Object of study. We investigate Hewlett Packard green LEDs (λmax = 525 nm at room temperature) based on an InGaN solid solution with quantum wells. Purpose of the Study. It is known that in light-emitting structures, optical characteristics are closely related to electrical characteristics. Analysis of the literature has shown the effect of the structure (number and width of quantum wells) on the electrical characteristics of the objects under study. Thus, the determination of the parameters of structures based on GaN and its solid solutions from the analysis of electrical characteristics is an urgent problem. The aim of this work is to test the application of the generalized recombination model for analyzing the reverse current-voltage characteristics of InGaN-based structures under illumination. Methods and Approaches Used. The paper considers the reverse current-voltage characteristics of structures with quantum wells under illumination with the same “junction-to-junction” LED from the point of view of the generalized model of recombination. The results of measurements and calculations using the generalized recombination model are compared with the distribution profile of the dopant obtained from the inverse capacitance-voltage characteristics. Main Results. It has been shown that three processes are involved in the formation of reverse current-voltage characteristics under illumination: photogeneration, recombination, and tunneling. When the structure is illuminated with the same LED in quantum wells, the photorecombination process plays a leading role. An expression has been obtained that describes the current through the sample in this case.

Keywords

• quantum well
• current transfer
• generalized recombination model
• photogeneration
• tunneling