Influence of p-type doping on the degradation of ZnSe laser diodes

We present results of optical degradation experiments on blue-green ZnSe-based diode laser structures. A micro-focused wavelength selectable laser is used for degradation and the luminescence from the degrading region is simultaneously recorded. The degradation speed at a given optical power density depends strongly on the doping of the structure and on the photon energy: undoped structures do not degrade, while the threshold photon energy to induce degradation depends on the degree of compensation in the p-doped layers. However, at high photon energies, an improvement in compensation does not slow down the degradation process, leading to the suggestion that the nitrogen acceptor itself is unstable under these conditions.