Growth of CdS layers to develop all-electrodeposited CdS/CdTe thin-film solar cells

The electrodeposition (ED) of CdS (continuous process) was investigated in detail with the aim of replacing chemical bath deposited (CBD) CdS (batch process) from the solar cell production process. This avoids the daily production of toxic waste and, hence, drastically reduces manufacturing cost. Material studies were carried out using voltammetry, X-ray diffraction, X-ray fluorescence, optical absorption, photoelectrochemical studies, and scanning electron microscopy. The main difference between the two processes is in the structure of material layers: ED-CdS is hexagonal while CBD-CdS is cubic. All other properties, the bandgap (2.42 eV), the electrical conduction type (n-type), and the grain size (~20 nm), remain very similar. The comparison of initial solar cell devices shows that ED-CdS layers have similar or superior performance in thin-film CdS/CdTe solar cells.