Photovoltage and carrier concentration profiles of ZnSe/ZnCdSe quantum well laser diodes

Abstract

In this paper, we report the fabrication of ZnSe/Zn 0.82 Cd 0.18 Se quantum well laser structures on GaAs substrates using nitrogen and iodine as p- and n-dopants but without the use of an epitaxial GaAs buffer layer. The lasers show excellent mode structure and emit at 474.8 nm at 77 K in the pulsed mode. We have used recently developed electrochemical profiling techniques such as capacitance–voltage ( C–V ) measurements to determine carrier concentration profiles through the laser structure and photovoltage spectroscopy (PVS) to profile the bandgaps. In particular, the PVS profiling is invaluable for determining the compositions of the layers within laser structures. This is the first time that such measurements have been obtained for II–VI laser structures.