Comparison the electron momentum and energy relaxation process in wurtzite GaN, InN and AlN by Monte Carlo method

摘要： At present, both transient and steady transport properties of III-V nitride semiconductors are researched, however, few research concerns about the momentum and energy relaxation process, which will be important during device designing. In order to clarify the fundamental physical process of the relaxation phenomenon, both momentum and energy relaxation process in wurtzite GaN, InN and AlN are studied with the help of classic three valleys Monte Carlo method. Our goal is to understand the relationship of relaxation rate with electric field, temperature and clarify the role of scattering mechanisms during momentum and energy relaxation process. The research shows that when the electric field and temperature are different, the main momentum and energy relaxation mechanisms may be different. For the lower effective mass in the lowest valley for InN, the electrons are more easily accelerated by electric field and scattered into the satellite valleys. The momentum relaxation time is much lower than that of energy relaxation time, the reason is that nearly all scattering mechanisms will relax momentum, but only polar optical phonon and inter-valley scattering relax electron energy. The research here can be used for construct the relaxation model or as a guide for device design.