Laser deposition of semiconductor thin films based on iron oxides

Narrow band gap iron oxide semiconductor films were grown with the laser chemical vapour deposition (LCVD) and reactive pulsed laser deposition (RPLD) techniques. For LCVD, 10 and 18 nm thick films, with composition Fe2O3-x (0 ≤ x ≤ 1), were deposited from iron carbonyl vapours with an Ar+ laser. Their band gap (Eg) results were of 0.46 eV and 0.66 eV, respectively. For RPLD, an iron target was ablated in low pressure oxygen atmosphere (0.1-1 Pa) by a KrF excimer laser. A number of pulses (4000-8500) increasing with oxygen ambient pressure was used for each deposition. The film thickness increased with pulse number from 100 to 240 nm. Eg increased in the range 0.13-0.34 eV with increasing oxygen pressure during deposition. It is shown that both LCVD and RPLD are appropriate technologies for the deposition of narrow variable band gap iron oxide semiconductor thin films