External-quantum-efficiency enhancement in quantum-dot solar cells with a Fabry-Perot light-trapping structure

Area of Science:

• Materials Science
• Optoelectronics
• Renewable Energy

Background:

• Quantum dot (QD) solar cells offer potential for high efficiency.
• Improving light absorption, especially in the near-infrared spectrum, is crucial for QD solar cell performance.
• Thin-film solar cells require effective light management strategies.

Purpose of the Study:

• To investigate the effect of light trapping on InAs/GaAs quantum dot solar cell performance.
• To enhance near-infrared photon absorption using a backside mirror and Fabry-Perot (FP) resonance.
• To optimize the positioning of QD layers for maximum light absorption.

Main Methods:

• Fabrication of a thin-film InAs/GaAs quantum dot solar cell with a backside mirror.
• Positioning of QD layers to coincide with Fabry-Perot resonance intensity peaks.
• Experimental measurement of external quantum efficiency.

Main Results:

• Achieved enhanced QD absorption near 1192 nm through FP resonance.
• Demonstrated an order of magnitude increase in external quantum efficiency at the FP resonance wavelength.
• Showcased the benefit of optimal QD layer positioning for light trapping.

Conclusions:

• Optimal positioning of QD layers within a thin-film structure utilizing FP resonance significantly enhances light trapping.
• This approach leads to a substantial improvement in the performance of InAs/GaAs quantum dot solar cells.
• Light trapping via FP resonance is a viable strategy for boosting solar cell efficiency.