Negative characteristic temperature of InGaN blue multiple‐quantum‐well laser diodes

Abstract

PACS 42.55. Px, 42.60.Lh We report anomalous temperature characteristics of InGaN laser diodes (LDs) emitting around 450 nm. Our blue LD shows negative characteristic temperature in the usual operation temperature range from 20 °C to 80 °C. This peculiar temperature characteristic is attributed to originate from unique carrier transport properties of InGaN quantum wells with high In composition, as deduced from the simulation of carrier density and optical gain. In addition, it is found that wall plug efficiency of the blue LD is even improved as temperature increases.