TiN and TiO{sub 2}:Nb thin film preparation using hollow cathode sputtering with application to solar cells

Journal Article · Sat Jul 15 04:00:00 EDT 2006 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.2180273· OSTI ID:20777340

Guo, S Y; Shafarman, W N; Delahoy, A E ^[1]

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1. Energy Photovoltaics, Inc., Lawrenceville, New Jersey 08648 (United States)

Titanium nitride (TiN) is well known for its excellent conductivity, inertness, and good optical reflectivity at long wavelengths. These properties make it a potential IR-reflective back contact material suitable for ultrathin Cu(In,Ga)Se{sub 2} (CIGS) solar cells. Using a pulsed power, 12 cm linear hollow cathode source fitted with Ti targets and with N{sub 2} as the reactive gas, TiN films were deposited on Mo-coated glass. The static deposition rate was 50 nm/min for a sputtering power of only 500 W. The high deposition rate indicates the advantage of the reactive environment, hollow cathode sputtering method, i.e., the reactive gas is excluded from the target. Electrical, optical, and physical properties of the films were measured. Resistivities in the range of 50-60 {mu}{omega} cm were achieved. Reflectance and x-ray diffraction measurements were conducted, and the effects of deposition parameters such as substrate bias and substrate temperature were studied. The optical emission from N and Ti atoms in the plasma was also studied. CIGS solar cells were successfully fabricated on TiN and a conversion efficiency of 12.3% was achieved. Transparent and moderately conductive TiO{sub 2} films doped with Nb were also prepared. The electrical and optical properties of these films are reported, and the reflectance of a-Si solar cells was reduced via incorporation of a TiO{sub 2}:Nb layer.

• OSTI ID: 20777340
• Journal Information: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Journal Name: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films Journal Issue: 4 Vol. 24; ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DEPOSITION
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
GLASS
HOLLOW CATHODES
NIOBIUM
REFLECTIVITY
SOLAR CELLS
SPUTTERING
THIN FILMS
TITANIUM NITRIDES
TITANIUM OXIDES
WAVELENGTHS
X-RAY DIFFRACTION