Title :
A novel cadmium free buffer layer for Cu(In,Ga)Se2 based solar cells
Author :
Hariskos, Dimitri ; Rückh, Martin ; Rühle, Ulfert ; Walter, T. ; Schock, Hans Werner
Author_Institution :
Inst. fur Phys. Elektronik, Stuttgart Univ., Germany
Abstract :
Solar cells based on Cu(In,Ga)Se2 were prepared replacing the `standard buffer layer´ CdS with a Inx(OH,S) y thin film. The film is deposited in a chemical bath (CBD) process using an aqueous solution containing InCl3 and thioacetamide. X-ray photoemission spectroscopy measurements were performed in order to characterize the growth kinetics and the chemical composition. The influence of different concentrations of InCl3 and thioacetamide in the solution on the electrical properties of the solar cells was studied by measuring the j-V characteristics and the spectral quantum efficiencies. Capacitance-voltage (C-V) measurements indicate that the high Voc values of devices with the novel buffer layer are correlated with narrower space charge widths and higher effective carrier concentrations in the absorber materials. The achieved conversion efficiency of approximately 15% using the cadmium free Inx(OH,S)y buffer demonstrates the potential of this process as an alternative to the standard chemical bath deposition of CdS
Keywords :
X-ray spectroscopy; carrier density; copper compounds; electrodeposition; electrodeposits; gallium compounds; indium compounds; photoelectron spectra; semiconductor device testing; semiconductor growth; semiconductor thin films; solar cells; space charge; 15 percent; C-V measurements; Cu(In,Ga)Se2 solar cells; CuInGaSe2; Inx(OH,S)y thin film; InCl3; X-ray photoemission spectroscopy measurements; absorber materials; buffer layer; chemical bath deposition; chemical composition; effective carrier concentrations; electrical properties; growth kinetics; j-V characteristics; semiconductor; space charge widths; spectral quantum efficiencies; thioacetamide; Buffer layers; Cadmium; Capacitance-voltage characteristics; Chemical processes; Kinetic theory; Performance evaluation; Photoelectricity; Photovoltaic cells; Spectroscopy; Transistors;
Conference_Titel :
Photovoltaic Energy Conversion, 1994., Conference Record of the Twenty Fourth. IEEE Photovoltaic Specialists Conference - 1994, 1994 IEEE First World Conference on
Conference_Location :
Waikoloa, HI
Print_ISBN :
0-7803-1460-3
DOI :
10.1109/WCPEC.1994.519815
