Developments of CuIn1-xGaxSe2 thin film solar cells using sputtering and selenization process

• Main Authors: Shuo-WenTsai, 蔡碩文
• Other Authors: Dung-Ching Perng
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/51547063927037396129

碩士 === 國立成功大學 === 電機工程學系專班 === 98 === A bi-layer CIGS film was used as the absorber layer to fabricate solar cell. The structure of the solar cell is SLG/Mo/CIGS(bi-layer)/CdS/i-ZnO/AZO/Ag. Two layers of CIGS films were prepared using CuGa and CuInGa metallic precursors involving both sputtering and selenization process. The metallic precursor of CuGa alloy was deposited onto Mo coated soda-lime glass substrate by sputtering using a Cu-Ga mixture target. Subsequently, the precursor was selenized under Se atmosphere by evaporator. The XRD patterns show that the CuGaSe2 film was found to be single phase while the MoSe2 peak was observed. The MoSe2 layer was suggested that the CIGS /Mo interface with this layer makes a favorable ohmic contact. As the CuGaSe2 was formed, a CuInGa metallic precursor layer was deposited on it using co-sputtering, followed by a selenization process in evaporator system. The crystalline of the selenized film was determined by XRD, and it shows that the single phase Cu(In,Ga)Se2 was observed. Finally, the CdS, i-ZnO , AZO and Ag were deposited on CIGS film in sequence. The cell was measured under the standard condition of AM1.5G spectrum (100 mW/cm2) at 25oC.The device parameters are as follows: open-circuit voltage (VOC) = 0.14V, short-circuit current density (JSC)= 6.49mA/cm2, fill factor (FF) = 28.69%, and efficiency = 0.26%. In this study, the sheet resistance of Mo back contact is 6.76 Ω/square. It is higher than the recorded 0.1Ω/square, and decrease the collection of carriers. The thickness of CIGS absorber layer is only 500 nm. The thickness is not efficient to absorb completely solar spectrum. A lower sheet resistance of Mo back contact and a thicker absorber layer are suggested to enhance the conversion efficiency.