Photovoltaic device performance of electron beam evaporated Glass/TCO/CdS/CdTe/Au heterostructure solar cells

• Main Authors: Punitha, K., Sivakumar, R., Sanjeeviraja, C.
• Format: Article
• Language: English
• Published: H. : ĐHQGHN 2018
• Subjects: CdTe; Grain boundary effect; Optical tailoring; Recombination losses; Ideality factor; Parasitic resistances; Conversion efficiency
• Online Access: http://repository.vnu.edu.vn/handle/VNU_123/62845; https://doi.org/10.1016/j.jsamd.2017.12.001
• Institution: Vietnam National University, Hanoi

We report on substrate temperature and Cu addition induced changes in the photovoltaic device perfor-mance of Glass/TCO/CdS/CdTe/Au heterostructures prepared by the electron beam evaporation technique. Prior to the photovoltaic study, the structural and optical properties of CdTe, CdTe:Cu and CdS/CdTe, CdS/ CdTe:Cu layers were studied. X-ray diffraction (XRD) analysis showed that the deposited films belong to a zinc blende structure. The existence of the Te peak in the XRDpattern revealed the presence of excess Te in the depositedfilmstructures, which confirmed thep-type conductive nature of thefilms. This was further substantiated by the electrical study. The low resistivity of 1 x 10 3 Ucm was obtained for 4 wt.% of the Cu-doped CdTe film,which may be due to the substitutional incorporation of more efficient Cu2þ(Cd2þ) into the CdTe lattice. The decrease in band gap with increasing Cu contentmay be attributed to the existence of shallow accept or level formed by the incorporation of Cu into the CdTe lattice. The efficiency of the cell was increased with increasing Cu concentration and the cell prepared at room temperature with 4 wt.% of Cu addition possessed the maximum conversion efficiency of 1.68%. Further, a good photoresponse of the device is achieved as theVocandIsc are increased with increase in the input power.