I need some sensitive thermopiles to make some radiation sensors for use in some atmospheric observations. They will be used to measure small temperature differences caused by different radiation fluxes incident on the two sides or faces. Can anyone tell me some links to, or names of manufacturers/suppliers of thermopiles (anywhere in the world)? Can I use thermoelectric power generation or cooling modules for my purpose? If yes, what is the difference between these thermoelectric modules and a traditional thermopile?

On the web I could find only heat flux sensors, which are essentially thermopiles, but they are a bit expensive considering that I need about 10 of them (each costs above 100$). But this could be because they are meant for measuring large heat fluxes and so they are made quite thin (less than 1 mm) and with high thermal conductivity. For my purpose they can be a few mm thick and with low thermal conductivity and that would necessitate much lower number of junctions, which would perhaps make them less expensive. Otherwise I found infrared sensors based on thin film thermopiles (used for non-contact temperature measurements), which are Ok, but for the fact that they have a narrow filed of view, whereas I need as large a field of view as possible (ideally 180 degrees).