Carrier leakage suppression utilising short‐period superlattices in 980 nm InGaAs/GaAs quantum well lasers

Short‐period Super Lattices (SSLs) have been proposed as a method of reducing carrier leakage in semiconductor lasers. SSLs increase the carrier confinement by increasing the effective barrier height due to the carriers being “reflected” from the SSL. Thermionically driven leakage of electrons from the quantum wells has been suggested as an important non‐radiative current path in (Al)GaAs based devices which is exacerbated at high temperatures. Due to the fact that the application of high pressure causes a reduction in the zone centre Γ–X minima splitting, pressure can be used to investigate the extent to which such leakage increase the threshold current. In this study, we compare devices with and without SSL layers and find direct evidence for leakage suppression in devices containing SSLs up to a temperature of 60 °C. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)