II-VI blue/green laser diodes

due to a burn-out at the evaporated gold contacts. By 1992 progress was made towards overcoming the lack of an ohmic contact to p-ZnSe. Two methods currently employed to provide contacts to p-ZnSe include the use of an intermediate layer of HgSe to reduce the Schottky barrier height as employed by the group at NC State in their LED devices, as well as the pseudograded Zn(Se,Te) contact proposed by the authors´. The Zn(Se,Te) graded contacts have proven a key element in reaching the objective of room temperature CW operation of 508nm laser diodes. In addition to their use in laser devices, the fact that the ohmic behavior of the Zn(Se,Te) graded contact persists to cryogenic temperatures permitted temperature-dependant Hall measurements to be performed.