AVS 58th Annual International Symposium and Exhibition
    Energy Frontiers Focus Topic Thursday Sessions
       Session EN-ThP

Paper EN-ThP9
Powder-Sputtered Cu(In,Ga)Se2 Thin Films: Nonstoichiometric Influences on Optical and Electrical Characteristics

Thursday, November 3, 2011, 6:00 pm, Room East Exhibit Hall

Session: Energy Frontiers Poster Session
Presenter: JiEun Jeon, Chosun University, Republic of Korea
Authors: N. Kim, Chosun University, Republic of Korea
J. Jeon, Chosun University, Republic of Korea
W. Lee, Chosun University, Republic of Korea
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The thin film solar cell efficiency of 19.2% (0.41 cm2) was accomplished by using Cu(In,Ga)Se2 (NREL, 2003), which has been fabricated by using the three stage co-evaporation process. There are two general methods for Cu(In,Ga)Se2 thin film fabrication: selenization after sputtering and thermal co-evaporation. The novel method of powder-sputtering was employed for the preparation of Cu(In,Ga)Se2 to deposit the thin film over the large area with a good uniformity without selenization of toxic H2Se because the co-evaporation method requires very strict controls during the deposition process of Cu(In,Ga)Se2 thin film. This method has the advantages of the production of target, change of stoichiometry, and easy doping of impurities. The composition of the starting powder target was changed by x = 0.1, 0.3, 0.5, 0.7, and 0.9 in the deposition process of Cu(Inx,Ga1-x)Se2 thin film while Cu/(In+Ga) ratio was ‘1’. The compositions of the starting powder target and the deposited samples with 1 μm-thickness were comparatively analyzed by electron probe microanalysis (EPMA). The crystal structure, surface morphology, optical properties, and electrical characteristics of Cu(Inx,Ga1-x)Se2 thin films were analyzed by using X-ray diffraction (XRD), atomic force microscope (AFM), UV-Visible spectrophotometer, and a Hall effect measurement system to investigate the influence of nonstoichiometry on the characteristics. The optimized composition was selected through the comprehensive analysis of the characteristics.