Résumé
Stimulated blue light emission has now been produced via electrical injection through a p-n junction using MBE grown II-VI wide bandgap semiconductors. This is not yet possible using the MOVPE technique, due to the somewhat unsuccessful realization of p-type doping of ZnSe. Microgun pumped lasers (where injection is achieved using an array of microtips as an electron gun) could be an alternative solution, but requires structures of high crystalline quality based on ZnSe/ZnCdSe. In this perspective, we have studied the MOVPE growth of ZnSe layers and ZnCdSe alloys and ZnCdSe based heterostructures using two different zinc precursor adducts: triethylamine-dimethylzinc (TEA:DMZ) and tetramethylmethylenediamine dimethylzinc (TMMD:DMZ). The growth conditions have been investigated and the solid composition versus gas phase composition has been studied for both adducts. The structural properties of ZnSe layers below the critical thickness have been studied versus the initial growth conditions and optimal growth conditions are proposed. Particular attention has been devoted to the investigation of the spectroscopic properties of the heterostuctures in view of the characterization of the abruptness of the heterointerfaces. Photoluminescence, reflectance and photoreflectance experiments will be presented.