Title :
The role of oxygen in CdS/CdTe solar cells deposited by close-spaced sublimation
Author :
Rose, Doug H. ; Levi, Dean H. ; Matson, Rick J. ; Albin, David S. ; Dhere, Ramesh G. ; Sheldon, Peter
Author_Institution :
Nat. Renewable Energy Lab., Golden, CO, USA
Abstract :
The presence of oxygen during close-spaced sublimation (CSS) of CdTe has been previously reported to be essential for high-efficiency CdS/CdTe solar cells because it increases the acceptor density in the absorber. The authors find that the presence of oxygen during CSS increases the nucleation site density of CdTe, thus decreasing pinhole density and grain size. Photoluminescence showed that oxygen decreases material quality in the bulk of the CdTe film, but positively impacts the critical CdS/CdTe interface. Through device characterization, they were unable to verify an increase in acceptor density with increased oxygen. These results, along with the achievement of high-efficiency solar cells (13% AM1.5) without the use of oxygen, led them to conclude that the use of oxygen during CSS deposition of CdTe can be useful but is not essential
Keywords :
II-VI semiconductors; cadmium compounds; semiconductor device testing; semiconductor growth; semiconductor thin films; solar cells; sublimation; vapour deposited coatings; vapour deposition; 13 percent; CdS-CdTe; CdS/CdTe solar cells; acceptor density; close-spaced sublimation deposition; grain size; interface; material quality; nucleation site density; oxygen; photoluminescence; pinhole density; Annealing; Cascading style sheets; Glass; Helium; Laboratories; Oxygen; Photovoltaic cells; Renewable energy resources; Substrates; Transistors;
Conference_Titel :
Photovoltaic Specialists Conference, 1996., Conference Record of the Twenty Fifth IEEE
Conference_Location :
Washington, DC
Print_ISBN :
0-7803-3166-4
DOI :
10.1109/PVSC.1996.564243
