Study of the band--gap shift in CdS films: Influence of thermal annealing in different atmospheres

TL;DR

This study investigates how thermal annealing in different atmospheres affects the band-gap shift in CdS films, aiming to optimize their properties for high-efficiency solar cells.

Contribution

It provides a detailed analysis of the band-gap evolution in CdS films subjected to various annealing conditions, identifying optimal processes for solar cell applications.

Findings

Optimal annealing conditions for high band-gap and low resistivity.

Thermal atmosphere significantly influences band-gap shift.

Procedure to improve CdS/CdTe solar cell performance.

Abstract

We study by photoacoustic spectroscopy the band--gap shift effect of CdS films. The CdS films were grown by chemical bath deposition and exposed to different annealing atmospheres over a range of temperature in which the sample structure is observed to change. We show the band--gap evolution as a function of temperature of thermal annealing and determine the process which produces the best combination of high band--gap energy and low resistivity. It allows us to know a possible procedure to obtain low--resistivity CdS/CdTe solar cells with high--quantum efficiency.