Demonstration of Solar Cell on a Graphite Sheet with Carbon Diffusion Barrier Evaluation

Area of Science:

• Materials Science
• Renewable Energy
• Semiconductor Physics

Background:

• Amorphous silicon (a-Si) solar cells offer flexibility and potential for lightweight applications.
• Graphite substrates provide desirable properties like lightness, conductivity, and flexibility for solar devices.
• Carbon diffusion from graphite into silver layers during fabrication can degrade device performance.

Purpose of the Study:

• To investigate the effectiveness of carbon diffusion barriers in amorphous silicon solar cells on graphite substrates.
• To evaluate silicon oxide (SiO₂) and tin oxide (SnO_x) as diffusion barriers.
• To optimize back reflector performance and thermal stability for flexible solar cells.

Main Methods:

• Fabrication of amorphous silicon solar cells with zinc oxide (ZnO) and silver (Ag) back reflectors on graphite substrates.
• Implementation of silicon oxide (SiO₂) and tin oxide (SnO_x) as carbon diffusion barriers.
• Thermal stability analysis using secondary-ion mass spectrometry (SIMS) to quantify carbon diffusion.
• Evaluation of deposition characteristics, reflectance, and solar cell performance.

Main Results:

• The incorporation of a carbon diffusion barrier improved the performance of the back reflector.
• Tin oxide (SnO_x) demonstrated superior performance as a carbon diffusion barrier compared to silicon oxide (SiO₂).
• Solar cells with SnO_x diffusion barriers exhibited enhanced thermal stability and overall performance.

Conclusions:

• Carbon diffusion barriers are crucial for the stability and performance of amorphous silicon solar cells on graphite.
• Tin oxide (SnO_x) is an effective material for preventing carbon diffusion in these devices.
• The developed flexible solar cell architecture with an SnO_x barrier shows significant promise for future applications.