Thermally enhanced external photoelectric emission theoretical study for transmissive exponentially doped GaAs photocathode
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Thermally enhanced photoelectric emission (TEPE) is a new proposed mechanism to improve solar cell efficiency at low temperatures (< 400K). In this paper, the mechanism of TEPE phenomenon is discussed based on the transmission-mode GaAs photocathode with exponential-doping structure. Parameters varying with temperature are quantitatively studied in the photoelectric emission process, such as diffusion length, absorption coefficient, escape probability and the drift length. Combining the variation of these parameters by temperature with the quantum efficiency of the transmissive-mode exponential-doping photocathode, the final TEPE quantum efficiency formula is derived, which proves and explains that the temperature has an auxiliary effect on the improvement of the photoemission quantum efficiency in low-temperature environment.
This work is sponsored by the Six Talent Peaks Project in Jiangsu Province-China (Grant No. 2015-XCL-008), the Fundamental Research Funds for the Central Universities-China (Grant No. 30916011206) and Qing Lan Project of Jiangsu Province-China (Grant No. 2017-AD41779).
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