Defect generation during constant current stress of InGaN laser diodes

We analyzed a group of InGaN-based laser diodes, with a peak wavelength around 418 nm, carrying out stress at a fixed current and room temperature. Electrical and optical characteristics were continuously monitored during the stress, and capacitance measurements and DLTS analysis were carried out in order to investigate the possible presence of defects within or around the active region. We observed the presence of a diffusion process in the first hours of stress. Capacitance-temperature measurements and DLTS allow us to identify shallow traps generated during the stress, in particular the presence of an acceptor-like trap, associated with line defects.