METALORGANIC CHEMICAL-VAPOR EPITAXY AND DOPING OF ZNMGSSE HETEROSTRUCTURES FOR BLUE-EMITTING DEVICES

Blue-green semiconductor laser diodes operating at room temperature ar e still the domain of wide bandgap II-VI compound semiconductors. CW o peration at room temperature and hours of lifetime were reported. Howe ver, the conductivity control, defect generation and the ohmic contact s still need improvement. Therefore we focused our work on the MOVPE g rowth and the optimization of ZnMgSSe/ZnSSe/ZnSe heterostructures as w ell as on nitrogen doping of ZnSe. To verify the layer quality charact erization was carried out by X-ray diffraction, electron probe microan alysis, electrical measurements and photoluminescence. ZnMgSSe/ZnSSe/Z nSe and ZnSSe/ZnSe quantum wells and superlattices were grown to inves tigate structural as well as interface properties. Electron beam and o ptical pumping was used to clarify the laser mechanism and to clarify the suitability of a MOVPE process to grow laser quality material. The electrical compensation of ZnSe doped with nitrogen is still controve rsially discussed whereas high n-type doping with chlorine was reprodu cible achieved. ZnSe:N doped at different growth conditions (II/VI rat io, growth temperature, nitrogen supply) using N-2 excited in a plasma source or by the use of nitrogen containing precursors was investigat ed to study the compensation mechanisms.