Abstract
In the light of the concept of developing in-line sputter technique for manufacturing Cu-III-IV2 thin-film solar cells, this thesis investigates the preparation and characterization of the CuInS2 based solar cell devices by using full RF reactive sputtering method in our laboratory. Because the CBD method in the traditional Cu-III-IV2 film solar cell technology is not compatible with the standard deposition process in the ULSI fabrication and it will produce much toxic waste as well, in the viewpoint of the industrial production and the environment protection we use ZnS to replace CdS as the buffer layer and use reactive sputter to replace CBD for a less toxic waste and higher efficient production. The structures of the studied device are p-i-n (Mo/ p-CuInS2 / n-ZnS /n-ZnO) and p-n (Mo/ p-CuInS2 / n-Al:ZnO) diode. The properties of each layer were measured by XRD, SEM, AES, EDX, and optical transmission analysis, resistivity. Each layer is almost the single phase as revealed in the diffraction patterns of XRD measurements. By varying the reactant gas flow rate, the composition, resistivity as well as other properties of the CuInS2 and ZnO films can be controled. For instance, the resistivity of CuInS2 layer is between 1.1~1410 Ω-cm, that of ZnO layer can vary from 1.6´10-1 to 2´103 Ω-cm, and so on. The J-V curve of the devices was measured by HP4156. Under illumination, a photon current of 32nA and photon Voltage of 0.16V has been detected on a device with the p-n diode structure. These results prove that our concept of in-line sputter for manufacturing CU-III-VI2 thin film solar cells is feasible. Although the conversion efficiency is still very poor now, it can be expected that the quality of every layer film and their interfaces can be improved effectively after using a RTP and a multi-target sputter system, and the device performance and the conversion efficiency can also be raised by optimizing the processing parameters in the not-long future.