Investigation Of Zn Diffusion In N-GaSb And The Fabrication Of GaSb Thermophotovoltaic Cell

P-N junction is central to a photovolatic(PV) cell, a"pseudo-closed"zinc diffusion process is used to form the P-N junction in GaSb thermophotovoltaic cells, the zinc diffusion process is investigated through experiments and theoretics in this dissertation.Zinc diffusion process in N-GaSb was studied with excessive, appropriate and insufficient quantity of diffusion source (zinc pellets). It is found out that: for diffusion temperature from 460 to 500℃, the zinc surface concentration of the diffused samples has nearly no change if the diffusion source is appropriate; when the diffusion time being constant, the logarithmic value of diffusion depth is linear with the diffusion temperature; when the diffusion temperature being constant, the diffusion depth is linear with the square-root of diffusion time.Kink-and-tail type zinc concentration profiles obtained with appropriate zinc pellets quantity were successfully simulated using the assumption that the vacancy mechanism mediated by VG 0aand kick-out mechanism mediated by IG+ a take effect at the same time. It is found out that: for diffusion temperature from 460 to 500℃, the logarithmic value of the zinc surface diffusion coefficient is linear with the reciprocal value of diffusion temperature; when the diffusion temperature being constant, both the zinc surface concentration and diffusion coefficient do not change with diffusion time.Several manufacturing technologies of GaSb cell are investigated, the GaSb cell sample is manufactured using the single-step zinc diffusion process, the method to enhance the quantum effciency is analyzed and the improvement is used in the manufacturing process.