Design optimization of micro-fabricated thermoelectric devices for solar power generation

Abstract

Solar thermoelectric power generation is known as an economic way to utilize the full solar spectrum energy with less dependency on daylight and weather conditions.Despite recent advances in the development of efficient thin film thermoelectric materials, micro-fabrication techniques for batch processing of solar thermoelectric power generators have not yet been pursued. This is mainly associated with the efficiency loss and low fabrication yield resulting from the small thickness of the thermoelectric layers. To address these issues, a planar thin film solar thermoelectric generator has been designed and optimized for micro-fabrication processing. This planar design possesses two attractive benefits. First, the length of the thermoelectric element can be flexibly optimized since it is not the same as the thickness of the deposited film. Second, deposition and patterning of both n- and p-type thermoelectric layers can be easily done using conventional micro-fabrication techniques. The application of thin film infrared reflecting coatings to enhance the efficiency was further considered. Theoretical analysis shows that the efficiency of this micro-machined solar thermoelectric device is comparable with the conventional solar cells while providing a less interruptive source of energy.