Efficient CdTe Solar Cells with an Al Back Electrode Enabled by a Mo/Cr Interfacial Modification Layer

Area of Science:

• Materials Science
• Renewable Energy

Background:

• Metallic aluminum (Al) is a cost-effective back electrode for cadmium telluride (CdTe) solar cells.
• Its low work function limits performance and widespread application.

Purpose of the Study:

• To enhance the performance of Al back electrodes in CdTe solar cells.
• To investigate the efficacy of a molybdenum-chromium (Mo/Cr) interfacial modification layer.

Main Methods:

• Fabrication and characterization of CdTe solar cells with Al, Mo/Cr-modified Al, and gold (Au) electrodes.
• Comparative analysis of electrical characteristics, interfacial transport, and device performance.
• Evaluation of mechanical adhesion and wear resistance.

Main Results:

• The Mo/Cr layer significantly improved interfacial transport and conductivity of Al electrodes.
• Optimized devices with Mo/Cr-modified Al achieved 15.68% efficiency, nearing Au electrodes (15.88%) and surpassing bare Al (13.83%).
• Mo/Cr-modified Al electrodes demonstrated superior mechanical adhesion and wear resistance.

Conclusions:

• The Mo/Cr interfacial layer effectively overcomes the limitations of Al back electrodes in CdTe solar cells.
• This low-cost, durable electrode architecture presents a viable alternative to noble metals for commercial thin-film solar technology.