Degradation of InGaN based green Laser Diodes: Kinetics and driving forces

Gallium Nitride based Light Emitting Diodes (LEDs) and Laser Diodes (LDs) are reliable devices which are emerging as the reference technology for light emission in the visible range of the electromagnetic spectrum. At the moment, a lot of effort is spent in order to achieve longer lifetimes for InGaN based green LDs, which could lead to the production of portable and highly miniaturized projection systems. Higher Indium concentration allows to cover the green spectral region, but leads to an higher defectivity of the active region, thus reducing the efficiency and the reliability of the device. In this paper, we will describe the main driving forces for the device degradation, their effects and the diffusion mechanism possibly responsible for the worsening of the performances, experimentally extracting its coefficient (on average, 5×10^-22 cm²/s).