Reducing optical losses in thermophotovoltaic systems

The reduction of optical losses in GaSb-based thermophotovoltaic converters via optimizing antireflection coatings and creating a back surface reflector on the photocell is reported. Upon the decrease in thickness of the GaSb substrate to 170 mu m along with the lowering of its doping level to n -2 & times;1017 cm-3, the reflection coefficient of low-energy (lambda < Eg) photons, R, is found to be - 0.7. A mathematical modeling at different temperatures and emitter materials shows that it is possible to increase the efficiency of thermophotovoltaic systems with tungsten and SiC emitters by 3% and 10.4% (at T = 1750 K), respectively, by using the back surface reflector with R - 0.7.

Automated summary

By reducing the thickness and doping level of GaSb substrate, as well as utilizing a back surface reflector with a reflection coefficient of -0.7, the efficiency of thermophotovoltaic systems can be increased, especially for systems using tungsten and SiC as emitter materials.