Zinc-diffused InAsSbP/InAs and Ge TPV cells

By means of LPE growth and Zn diffusion, TPV cells and mid-IR photodetectors based on p-InAsSbP/n-InAsSbP/n-InAs and p-InAs/n-InAs structures have been fabricated with the photosensitivity widened in the infrared range (2.5-3.4 μm). Zinc - diffused p-n Ge-based TPV cells have been fabricated with external quantum yield as high as 0.9-0.95 and high short circuit current of 31.6 mA/cm² under sunlight with cut-off at λ< 900 nm AMO spectrum. The Ge-based TPV cells with back-surface mirror demonstrate reflection of 85% for the sub-bandgap photons. The Ge cells with GaAs window have been developed for PV and TPV applications with using the combination of liquid-phase epitaxy and Zn-diffusion processes. Efficiency of more than 5% has been measured in p-GaAs/p-Ge/n-Ge cells under cut-off (λ<900 nm) AM1.5 spectrum at photocurrent densities of 3+20 A/cm².