Direct Plasmonic Solar Cell Efficiency Dependence on Spiro-OMeTAD Li-TFSI Content

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• The Internet of Things (IoT) requires sustainable energy solutions beyond single-use batteries.
• Aesthetics and technical performance are key drivers for adopting energy harvesting technologies.
• Transparent solar cells offer a promising avenue for integrating power sources without compromising visual appeal.

Purpose of the Study:

• To investigate the impact of Li-TFSI dopant concentration on the performance and transparency of semi-transparent, direct plasmonic solar cells (DPSCs).
• To determine the optimal doping conditions for maximizing transparency and energy conversion efficiency in DPSCs.
• To understand the relationship between doping, charge dynamics, and optical properties in these devices.

Main Methods:

• Fabrication of semi-transparent DPSCs with varying Li-TFSI dopant concentrations in the hole transport layer.
• Optical characterization to measure transparency across the visible spectrum (450-800 nm).
• Electrical performance testing and analysis of charge carrier dynamics using electron-phonon lifetime measurements.

Main Results:

• Optimal device performance was achieved at approximately 33% relative concentration of Li-TFSI to spiro-OMeTAD.
• Increased Li-TFSI content modulated transparency and effective conductance, with an optimal balance found.
• Charge extraction remained unaffected by Li-TFSI content, with hot electron and hole injection occurring within 150 fs.
• The spiro-OMeTAD layer effectively reduced nanoparticle backscattering, enhancing overall cell transparency.

Conclusions:

• Precise tuning of the spiro-OMeTAD doping level is crucial for achieving high transparency (>80%) in DPSCs while retaining plasmonic properties.
• Optimized doping enables the integration of sustainable, aesthetically pleasing power sources for IoT applications.
• These findings pave the way for more widespread adoption of transparent solar technology in low-power electronic devices.