Optics of CdS/CdTe thin film photovoltaics

Optical probes based on multichannel spectroscopic ellipsometry (SE) have been applied at all stages of the development of CdS/CdTe thin film photovoltaics (PV). Real time SE during materials fabrication has provided insights into nucleation, coalescence, and structural evolution of CdS and CdTe films. The deduced optical properties have provided insights into material density, strain, and defect density. The optical properties have also served as a database for analyzing complete PV stacks. Applications of this database include depth profiling of materials and devices before and after CdCl₂ treatment, as well as off-line mapping and on-line monitoring of large area PV plates and modules.