Performance Improvement of the GaSb Thermophotovoltaic Cells With n-Type Emitters

GaSb cells are commonly fabricated using Zn diffusion into n-GaSb, and in this paper they have been designed inversely using Te diffusion into unintentionally p-doped GaSb. Numerical simulation is used to analyze the cell performance. We found that a GaSb cell with n-type emitters showed a significantly higher output power density compared with that of the cell with p-type emitters under 1500 K-blackbody radiation. The performance improvement is owing to the good matching of the diffusion length of minority carriers with the depth of their moving regions. Several parameters that affect the cell performance were analyzed, such as doping depth, substrate thickness, and surface recombination velocity. The cell performance was evaluated under low temperature radiations and found to have huge potentials for the use in low-temperature thermophotovoltaic systems.