CdTe/CdS thin film solar cells in the substrate configuration on a single-wall carbon nanotube back contact

CdTe and CdS thin films have been grown by vapor assisted transport in a commercial deposition process onto carbon single-wall nanotube (SWNT) thin films of various thickness at temperatures in excess of 570 °C. The structure and morphology of the films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The SWNT layers were undamaged by the high temperature deposition process, and the semiconductor layers exhibited good crystal quality and grain orientation. Solar cells were fabricated in the substrate configuration (SWNT/CdTe/CdS/TCO) and current density/voltage measurements were obtained. Devices exhibited a V_oc of 540 mV and an efficiency of 4% without optimization. These results indicated the possibility of using SWNT layers as a back contact layer for CdTe/CdS devices grown in the substrate configuration.