Monte Carlo Simulation Of Electron Transport Properties In Zns

The electronic transport of bulk ZnS has been calculated by Monte Carlo simulations. Non-parabolicity model is adopted to calculate band model which includes two energy sub-bands for conduction band. The main work includes building the structure of ZnS by using mathematical method firstly, calculating the scattering rates. initialing conditions of electron motion, calculating free flight time, choosing scattering mechanisms and the final state, and analyzing the simulations results. Several scattering mechanisms are included such as acoustic phonon scattering, polar optical phonon scattering, intervalley scattering, ionized impurity scattering, and impact ionization scattering. Also we adopt self-scattering to simple the calculating of flying time.The simulation results show that when the field is low, almost electrons occupy theΓvalley, the average electron energy is equal to electron thermal equilibrium energy. When the field reaches 170 kV/cm, the peak value of electron drift velocity appers and the value is 1.454×107V/cm. Furthermore, by the field increasing, the electron drift velocity decreases. The simulation curve appers differential negative-resistance. When the field increases, the average electron energy increases, and the electrons transit to the higher energy-valley. The electron number inΓvalley decreases, and the electron number in L, X, Z valley increases. When the filed is 1 MV/cm, the electron occupancy in L, X, Z valley is 14.44%.19.32%, 6.4% respectively. The impact ionization mechanism is important to the transport of electron at high-field. The impact ionization occurs when the electron energy achieves 3.8 eV. The impact ionization rate increases along with field increases. At low field. the average drift mobility is between 120cm2 /V·s and 170cm2 /V·s.The non-parabolicity Monte Carlo results of ZnS coincide with the Monte Carlo results reported by other authors. The non-parabolicity model and calculation are simple. This method can be used in other relative materials.