High-Efficiency Polycrystalline CdTe Thin-Film Solar Cells with an Oxygenated Amorphous CdS (a-CdS:O) Window Layer: Preprint

Conference · Wed May 01 00:00:00 EDT 2002

DOI:https://doi.org/10.1109/PVSC.2002.1190619· OSTI ID:15006968

Wu, X; Dhere, R G; Yan, Y; Romero, M J; Zhang, Y; Zhou, J; DeHart, C; Duda, A; Perkins, C; To, B

In the conventional CdS/CdTe device structure, the poly-CdS window layer has a bandgap of {approx}2.4 eV, which causes absorption in the short-wavelength region. Higher short-circuit current densities (Jsc) can be achieved by reducing the CdS thickness, but this can adversely impact device open-circuit voltage (Voc) and fill factor (FF). Also, poly-CdS film has about 10% lattice mismatch related to the CdTe film, which limits the improvement of device Voc and FF. In this paper, we report a novel window material: oxygenated amorphous CdS film (a-CdS:O) prepared at room temperature by rf sputtering. The a-CdS:O film has a higher optical bandgap (2.5-3.1 eV) than the poly-CdS film and an amorphous structure. The preliminary device results have demonstrated that Jsc of the CdTe device can be greatly improved while maintaining higher Voc and FF. We have fabricated a CdTe cell demonstrating an NREL-confirmed Jsc of 25.85 mA/cm2 and a total-area efficiency of 15.4%.

• Research Organization: National Renewable Energy Lab. (NREL), Golden, CO (United States)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC36-99-GO10337
• OSTI ID: 15006968
• Report Number(s): NREL/CP-520-31429; TRN: US200412%%537
• Resource Relation: Conference: Conference title not supplied, Conference location not supplied, Conference dates not supplied; Other Information: PBD: 1 May 2002; Related Information: Prepared for the 29th IEEE PV Specialists Conference, 20-24 May
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
ABSORPTION
EFFICIENCY
FILL FACTORS
ORGANIC COMPOUNDS
SOLAR CELLS
SPUTTERING
THICKNESS
VOLATILE MATTER
PV
OXYGENATED AMORPHOUS CDS
HIGH-EFFICIENCY POLYCRYSTALLINE
THIN-FILM SOLAR CELLS
SHORT-WAVELENGTH REGION
CADMIUM TELLURIDE (CDTE)
PHOTOEMISSION SPECTROSCOPY (XPS)
X-RAY DIFFRACTION
RAMAN SPECTRA
ATOMIC FORCE MICROSCOPY (AFM)
SOLAR ENERGY - PHOTOVOLTAICS