Deposition of chromium oxide thin films with large thermoelectromotive force coefficient by reactive pulsed laser ablation

Thin films of chromium oxides were deposited on Si substrates by KrF laser ablation of a chromium target in O(2) atmosphere (0.05-5.0 Pa). Films exhibit semiconducting properties with band gap increasing (0.32-0.71 eV) with increasing pressure from 0.05 to 1.0 Pa. The largest values of the thermoelectromotive force coefficient S (similar to 3.5-4.5 mV/K) were measured in the temperature range 270-290 K for the film deposited at 1.0 Pa. The S coefficient decreases in the same temperature range for the film deposited at lower oxygen pressures.