Abstract:
Thin films of the p-type semiconductor, barium copper sulfide fluoride (BaCuSF) were deposited using pulsed laser deposition. Similar p-type conductivity in Cu2O is caused by copper vacancies. Addition of copper dopant is proposed as a method for filling the copper vacancies in BaCuSF. The films are characterized to determine quality using x-ray diffraction (XRD), atomic force microscopy (AFM), optical absorption, Seebeck, and resistivity measurements. The optimal deposition parameters with no added copper are: substrate temperature of 525 ºC, argon gas pressure of 10-5 Torr, target-substrate distance of 2 inches, and a pulse repetition rate of 3 Hz. Copper is added to films produced at optimal deposition parameters at pulse ratios of 1000:1000 to 12:1000. Resistivity measurements are compared with theoretical copper content of the film to determine the success of the dopant. The film produced with a pulse ratio of 40:1000 has the closest to stoichiometric copper as well as the highest resistivity. This corresponds well with the filling of copper vacancies.
