A LED-based Functional Light Source for the Characterization of Thin Film Solar Cells

TL;DR

This paper presents a customizable LED-based light source for detailed characterization of thin film solar cells, enabling flexible wavelength, intensity, and timing control to improve research efficiency.

Contribution

The authors developed a versatile, cost-effective light source with adjustable parameters, enhancing the investigation of solar cell properties compared to traditional, limited-functionality sources.

Findings

Successfully characterized CdTe and CZTS solar cells using the new light source.

Demonstrated control over photovoltaic and impedance properties through wavelength and illumination period adjustments.

Validated the light source's potential for photophysical and photochemical studies in renewable energy materials.

Abstract

A light source of selective functionalities of wavelengths, illumination periods, and intensities is desirable for investigating performance parameters as well as the quality of different layers and interfaces of solar cells. Conventional light sources used for these types of research are expensive, space-consuming, cumbersome to work with, and have limited functionalities. We have developed a light source with variable wavelength, intensity, and illumination period to address these issues using an illumination period control unit, voltage regulator, neutral density filter, alterable light emitting diodes, etc. As a proof-of-concept, we employed our constructed light source to investigate the intensity, wavelength, illumination period modulated photovoltaic, and impedance properties of inorganic thin film solar cells such as cadmium telluride (CdTe) and copper zinc tin sulfide (CZTS) using lights of wavelength 410, 520, and 635 nm. We hope to use this light source for photophysical and photochemical studies of metal oxide materials used for renewable energy research.