Improvement strategy evaluation from coupled energy-flow perspective on the GaSb thermophotovoltaic cell

Thermophotovoltaic (TPV) emerges as a novel high-efficiency generation technology, showcasing enormous potential in various sustainable energy solutions. Aiming to understand the complex conversion process between radiative, electrical and thermal energies within TPVs, a multi-physics coupled model is established. From the heat generation, temperature and carrier perspectives, the output performance is analyzed in detail. Under 1200 K black-body radiation, the energy loss distribution in the GaSb cell is analyzed meticulously, where Joule heat (40.4 %), surface recombination heat (23.1 %) and thermalization heat (20.8 %) play predominant roles. As it stands, the cell temperature rises to a maximum of 317.0 K with a cooling intensity of 300 W/(m²·K). The minimum of the average cell temperature (approximately 312.3 K) occurs at the optimized working voltage of 0.3 V. Subsequently, the electrical characteristics are illustrated. The results indicate a maximum output power underestimation of 4.6 % compared to the uncoupled isothermal case. Based on the coupled model, a quantitative analysis of the anti-reflection coating (ARC), the structural adjustment (SA) and the selective emitter (SE) is conducted. The results reveal that the ARC case exhibits the most enhancement in the output power (55.3 %) followed by the SA case, which effectively improves it by 12.2 %. Although the SE case partially decreases the output power (−9.8 %), it shows promise in promoting conversion efficiency. Integrating the above strategies, the TPV system achieves an impressive conversion efficiency of 29.38 %, representing a 76.46 % improvement compared to the prototype with the cell only.