Thermoelectric microsensor for pressure and gas concentration measurement

Narrow-band gap semiconductors n-Bi2Te3 (n-type) and p-(Bi1−XSbX)Te3 (p-type) have been elaborated by metal organic chemical vapour deposition. The thermoelectric and electric properties of the best films grown under optimal conditions are presented. In the same growth, a pressure sensor and gas concentration sensor based on n-Bi2Te3 and p-(Bi1−xSbx)Te3 thermoelectric materials are constructed using the thin film technology. The deposited materials are the best thermoelectric energy converters that allow a high sensitivity and a value of 5 mV torr−1 mW−1 for the pressure sensor has been found. These sensors have an integrated thermocouple with a thermoelectric power equal to 420 μV K−1. The thermal exchange of the heating surface, at a low heating power, with the surrounding gas is the principal function of these sensors.