NOVELTY - A thermoelectric device comprises a substrate; a thermoelectric layer (e.g. lead telluride), and a barrier layer (e.g. lead oxide-tellurium dioxide that is formed by partially oxidizing the thermoelectric film to form an oxide layer. The oxide layer is melted to form the barrier layer. The thermoelectric layer is vapor deposited on the substrate using a vapor deposition system at a vacuum of 10-2 - 10-9 torr.    USE - As a thermoelectric device useful in refrigerator, a thermoelectric generator, Peltier device (claimed), and thermoelectric heat pumps for direct conversion of heat into electricity or for direct conversion of electricity into heat.    ADVANTAGE - The thermoelectric device comprises multiple thermoelectric layers separated by electrical insulating barrier layers. The thermo power conversion efficiency (ZT) factor of the thermoelectric device is at least 0.5 (preferably at least 2.5). The thermoelectric layer is less than 300 (preferably less than 100) nm in thickness. The thermoelectric film thickness is such that the ZT factor is enhanced through the effects of quantum confinement effects such that the ZT factor is higher than that of corresponding bulk material. The glass layer has been determined to be an effective insulator while the layer of lead telluride (PbTe) underneath the oxide layer retains its high electrical conductivity and high Seebeck coefficient. Thin films of PbTe can be tailored to exhibit n-type or p-type conduction quite easily, either by changing the stoichiometry of lead and tellurium or by adding some minor components/impurities. The lead oxide-tellurium dioxide (PbO-TeO2) has been observed to form excellent glasses without substantially crystallizing if certain minor additives are included. The barrier layer prevents oxygen from interacting with the thermoelectric material, thus impairing the thermoelectric performance of the thermoelectric material. The thermoelectric device can be produced by an automated process, producing hundreds (preferably thousands) of layer, one on top of other, and separated by insulating glass layer.    DETAILED DESCRIPTION - A thermoelectric device comprises a substrate; a thermoelectric layer (e.g. lead telluride); and a barrier layer (e.g. lead oxide-tellurium dioxide that is formed by partially oxidizing the thermoelectric film to form an oxide layer. The oxide layer is melted to form the barrier layer. The thermoelectric layer is vapor deposited on the substrate using a vapor deposition system at a vacuum of 10-2 - 10-9 torr. The thermoelectric device is subjected to flash-heating to convert the oxide layer from a porous material into a dense glass material. The thickness of the thermoelectric layer decreases with increased oxidation time. The thickness of the oxide layer increases with increased oxidation time.    DESCRIPTION OF DRAWING(S) - The figure shows a top view of the thermoplastic film layer of the thermoplastic device.    electrodes (20)    thermoelectric film layer. (22)