Numerical Analysis Of The Electrostatic Potential Of The Based On Semiconductor Heterostructure

In order to design the quantum point contact (QPC) devices based on the semiconductor heterostructure, electrostatic potential distribution and control methods of the QPC are needed to be considered. In this paper , method for the numerical calculation of the electrostatic potential in the QPC is studied ,and the factors that affect the QPC electrostatic potential are analyzed.In this paper, based on the theory and development of QPC applied in the charge-sensitive detector, the research direction of the electrostatic potential of the QPC is determined by the study of QPC's basic structure and the analysis of principles and factors of the QPC as a charge-sensitive detector . On the basis of research to the QPC's structure and the factors impact the electrostatic potential, physical model of the QPC is established, and the quasi-3D mathematical model for calculating QPC's electrostatic potential is studied by the Quantum Mechanics. Self-consistent solving the coupled Poisson and effective mass equations is based on the finite difference method, so the distribution of QPC electrostatic potential and electron density is acquired. According to the results calculated, the effect of the gate structure and gate voltage on the electrostatic potential is analyzed. Electrical potential changed with the different gate shape, gate area or gate voltage changes is discussed. Electric potential of the numerical results, substituted into the calculation program of the QPC conductance, is applied to the numerical calculation of the QPC conductance.The results in this thesis play the guiding role on the theoretical and engineering for design and optimization of the QPC device, and is the foundation for the development of CAD tools of the QPC.