Electrodeposition of CuIn1-xGaxSe2 Materials for Solar Cells:

Bhattacharya, R. N. ; Fernandez, A. M. ; Batchelor, W. ; Alleman, J. ; Keane, J. ; Althani, H. ; Noufi, R. ; Ramanathan, K. ; Dolan, J. ; Hasoon, F. ; Contreras, M.

National Renewable Energy Laboratory (U.S.)

关键词: Electron-Probe Microanalysis;    Conversion Efficiency;    Solar Cells;    36 Materials Science;    Capacitance-Voltage;   

DOI  :  10.2172/15002206
RP-ID  :  NREL/TP-590-32775
RP-ID  :  AC36-99-GO10337
RP-ID  :  15002206

美国|英语

来源: UNT Digital Library

【 摘 要 】

This report describes our scientific understanding of the CIGS materials system, solar cells, and processes. Through DOE support, the investigators developed much of the technology and device fabrication infrastructure applied to electrodeposited (ED) materials. The electrodeposition process is simple and fast, and can synthesize multinary precursors for subsequent processing into CuInxGa1-xSe2 (CIGS) thin-film absorbers for solar cells. The device fabricated by using electrodeposited CIGS precursor layers resulted in total-area conversion efficiencies up to 15.4%. As-deposited precursors are Cu-rich CIGS. Additional In, Ga, and Se (up to 50%) are added to the precursor films by physical vapor deposition (PVD) to adjust the final semiconductor film composition to about Cu0.95In0.75Ga0.25Se2. The ED device parameters are compared with those of an 18.8% PVD device. The tools used for comparison are current-voltage, capacitance-voltage, and spectral response characteristics. The individual parameters of the device prepared from ED precursor films showed no significant deterioration from those of the PVD CIGS cells. We also developed a buffer-based electrodeposition bath. Using the buffer solution enhances the stability of the electrodeposition process, and no metal oxides or hydroxides precipitate out of the solution. The buffer-based bath also deposits more gallium in the precursor films. As-deposited precursors are stoichiometric or slightly Cu-rich CIGS. Only a minimal amount (5%-10% of total materials) of indium was added to the ED precursor films by PVD to obtain a 9.4%-efficient device. In general, the films and devices have been characterized by inductively coupled plasma spectrometry, Auger electron spectroscopy, X-ray diffraction, electron-probe microanalysis, current-voltage, capacitance-voltage, and spectral response.