Tunnel Effects in Luminescence Spectra of InGaN/AlGaN/GaN Light-Emitting Diodes

Abstract

ABSTRACTTunnel effects in luminescence spectra and electrical properties of blue InGaN/AlGaN/GaN LEDs were studied. The tunnel radiation in a spectral region of 2.1–2.4 eV predominates at low currents (J<0.2 mA). The role of tunnel effects grows as the maximum of the main blue line in LEDs is shifted to short wavelengths. The position of the tunnel maximum ћωmax is approximatly proportional to the voltage eU. The spectral band is described by the theory of tunnel radiative recombination. Current-voltage characteristics have a tunnel component at low direct and reverse currents. The distribution of charged impurities was received from dynamic capacitance measurements. There are charged layers at heterointerfaces and adjacent compensated layers in the structures. There is a high electric field in the active layer. The energy diagram is analysed.