Surface chemistry of Cu/sub x/S and Cu/sub x/S/CdS determined from x-ray photoelectron spectroscopy

Journal Article · Sat Jun 01 04:00:00 EDT 1985 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.335283· OSTI ID:6009166

Partain, L D; Schneider, R A; Donaghey, L F; McLeod, P S

X-ray photoelectron spectroscopy spectra measured on copper sulfide (Cu/sub x/S) films showed that a thin surface reaction product containing Cu in the +2 valence state was formed on Cu/sub x/S films exposed to air for 46 h at 40 /sup 0/C and 90% relative humidity. An entirely different Cu/sub x/S surface reaction product layer was formed in dry air at 170 /sup 0/C for 30 min and it contained sulfur in the +6 valence state. The copper (Cu) valence state in Cu/sub x/S was not found to be +2 even when the x value was less than 1.9. When the argon sputter-cleaned surface of Cu/sub x/S or Cu/sub x/S/CdS films was exposed to room-temperature air for 10 min, cadmium (Cd) atoms appeared on the Cu/sub x/S surface. X-ray powder diffraction patterns showed that CuO and CdS reacted at 500 /sup 0/C in flowing nitrogen to form Cu/sub 2/S and CdO. This cation exchange between CdS and copper oxide may explain the surface Cd on the Cu/sub x/S films. The standard free energy of reaction between CuO and CdS is positive while that between Cu/sub 2/O and CdS is negative. These results indicate a method for stabilizing Cu/sub x/S/CdS solar cells against degradation.

• Research Organization: Chevron Research Company, Richmond, California 94802-0627
• OSTI ID: 6009166
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 57:11; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
CADMIUM COMPOUNDS
CADMIUM SULFIDE SOLAR CELLS
CADMIUM SULFIDES
CHALCOGENIDES
CHEMICAL REACTIONS
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER SULFIDES
DIFFRACTION
DIRECT ENERGY CONVERTERS
ELECTRON SPECTROSCOPY
ELEMENTS
EQUIPMENT
INORGANIC PHOSPHORS
NITROGEN
NONMETALS
PHOSPHORS
PHOTOELECTRIC CELLS
PHOTOELECTRON SPECTROSCOPY
PHOTOVOLTAIC CELLS
SCATTERING
SOLAR CELLS
SOLAR EQUIPMENT
SPECTROSCOPY
SPUTTERING
STABILIZATION
SULFIDES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION