How Efficient Can Solar Photovoltaics Become?
Costs for some solar photovoltaics (PV) have dropped sharply over the past few years, but efficiency has not necessarily followed suit. The search for PV modules that are both low-cost and highly efficient continues at government research labs.
Plasmonic energy conversion, which generates “hot” (highly energetic) electrons in plasmonic nanostructures through the electromagnetic decay of surface plasmons, is one promising solution. It offers potentially high conversion efficiencies (greater than 22 percent) while keeping fabrication costs low, given the right materials, architectures, and fabrication methods.
César Clavero, an Environmental Energy Technologies Division researcher at Lawrence Berkeley National Laboratory, surveyed the current state of the technology. The resulting paper, “Plasmon-induced hot electron generation in nanoparticle/metal oxide interfaces for photovoltaic and photocatalytic devices,” was published in the January 30 issue of Nature Photonics.
The review found that two key factors promote high conversion efficiencies: fast hot-electron injection before recombination and optimum carrier regeneration. The research also suggests that by combining multiple metals and conducting oxides, the devices will be able to generate electricity from more spectrums of solar radiation, thereby increasing electricity production.
Clavero found that material, size, and shape of the plasmonic nanostructures are the most important design factors affecting the localized surface plasmon resonance (LSPR) electron-generation processes. Plasmonic energy conversion could solve the problem of efficiency decreases at higher temperatures, which affects conventional PV cells, because the efficiency with plasmonic structures actually increases with temperature.
While titanium dioxide has been the most-used semiconductor for plasmonic energy conversion, Clavero suggests that the valence bands of zinc oxide, cerium oxide, and silver bromide could also make them efficient electron acceptors. Further studies will need to determine the most efficient semiconductor material.
This work was supported by the Department of Energy’s Office of Energy Efficiency and Renewable Energy, Office of Building Technology.
- How "Fixed" is the Fixed Price Product?
- NAEM Trends Report: Planning for a Sustainable Future
- Expert Q and A: Tips for Automating your Energy Data
- 2014 Environmental Leader Product and Project Awards
- What You Need to Know About Demand Charges
- Alarms Management: The Future is Now
- The Guru’s Guide: Implementing Environmental ERP Systems
- LED Myths and Facts
- EHS Managers: The Evolution from Necessary Evil to Vital Leaders
- 2014 Energy and Sustainability Predictions: Findings from Leading Professionals
- Energy Procurement in 2014: Products & Programs to Optimize Savings
- BUYING STRATEGIES IN A VOLATILE MARKET: What Businesses Need to Know about Retail Electricity Procurement
- Smart Building Technology: The Key to Comprehensive Building Performance
- What Energy Managers Need to know about Procuring Natural Gas: Guidance for 2014 Natural Gas Contracts
- Energy Optimization from the Boiler Room to the Board Room