Résumé
GaN and its low-dimensional structures have been extensively investigated in the past years because of their excellent optical and electrical properties. Progress in this field is so fast that the nitrides are expected to revolutionize the optoelectronics and electronics in the new century. The nature of high thermal conductivity, high luminous efficiency, and mechanical robustness have made the GaN and its alloys the superior material system for light-emitting devices operation from the UV to the entire visible spectra region [1). In addition, new applications in high power, high temperature, and high frequency electronic devices based on GaN field effect transistors and heterobipolar transistor are under extensive exploration.