Power Generation by Zinc Antimonide Thin Film under Various Load Resistances at its Critical Operating Temperature

Thermoelectric generators (TEGs) use the Seebeck effect in semiconductors for direct conversion of heat to electrical energy. Zinc antimonide films were deposited on polished fused silica substrates by co-sputtering method in Aarhus University. This study focuses on stability of zinc antimonide thin films operating under different load resistances at around its critical operating temperature, 400 ᵒC.
The thermoelement is subjected to constant hot side temperature and to room temperature at the cold junction in order to measure the thin film TEG’s sample performance. The nominal loads equal to 10, 15, 20, 25, 30, 35, 40, 45… 175, and also 200 Ohms were applied. The results show that the value of the Seebeck coefficient is 0.0002 [V/K] for the specimen, which is in agreement with quantities of other zinc antimonide bulks materials in literature. The results also show that the voltage slightly reduces during unload conditions, although it is expected that by eliminating load in each step, the initial amount of voltage exactly repeats. Similar behavior is observed for Seebeck coefficient distribution versus time of working particularly in lower load resistances. Based on variation of load resistance, the maximum power output is tracked. Finding this critical point is very important for design of TEGs. Maximum power output was almost 9.8 μW corresponding to the external load between 130 and 150 ohms.