This invention describes a process for sputter deposition of thin films of alloys of Bi2Te3, Sb2Te3 and Bi2Se3 for thermoelectric energy conversion. The approach allows deposition of these films on glass and flexible substrates such as Kapton. The process was used to deposit n-type and p-type films that exhibit properties nearly as good as measured for bulk materials. A single thermocouple was formed from n-type and p-type films that produced 3 millivolts under a temperature difference of 10 degrees centigrade. This result demonstrates that miniature high-voltage, microwatt power sources can be constructed from thin film arrays deposited as described by the disclosed process.