The “black swan theory” refers to real events beyond the realm of normal expectations–and that’s how an international team of researchers at SciTech Solar (lead by a former professor emeritus from Penn State) are referring to their latest breakthrough, a technology that allows for ultra high-efficiency solar cells to generate DC, or direct current electricity.
Why is this such a big deal in the solar world? Apparently because it makes possible the design and fabrication of a new class of solar energy converters which could allow for a dramatic increase in energy conversion efficiency and cost savings of solar cells. According to Penn State, this is a technology that can successfully compete with today’s semiconductor-based solar cells while exceeding efficiencies and decreasing costs. They’re hailing it as a scalable, sustainable, adaptable and environmentally-friendly technology that will allow manufacturers to quickly and economically shift to new materials if a shortage of any one type occurs.
image via SciTech Associates
The technology is based on a new “optical rectification” process that makes use of a simple, cost-effective, single element system that extracts energy from the solar spectrum from the infrared through the visible light spectrum. This broad-spectrum absorption significantly contributes to the gain in efficiency as compared to today’s solar cells, allowing these single element cells to act simultaneously as both a receiving antenna and as a rectifier to absorb and convert solar energy to an electric current. Such a device is historically termed a “rectenna” and was developed for microwave power transmission.
In extensive computer simulations, scientists from United States, Belgium and Korea performed quantum-mechanical calculations that agree with the rectification results of the actual operation of the device, showing rectification of light throughout the visible region and a significant DC current output. The scientists obtained efficiencies comparable to and exceeding those of current solar cell devices (efficiencies as high as 50% were recorded). The scientists are currently developing prototype devices which include more robust antenna structures and plasmonic effects to enhance output and efficiency.
United States Patent Application 20090308443 Kind Code A1 Cutler; Paul H. December 17, 2009
Apparatus and system for a single element solar cell
A device for receiving and converting incident radiation into DC current, the device including a transparent conductor, at least one point-contact diode, the at least one point-contact diode having a nanowire/mCNT providing a receiving antenna function and a rectification function, a thin insulating layer situated between the transparent conductor and the nanowire/mCNT, and a point contact junction at which the nanowire/mCNT contacts the thin insulating layer.
| Inventors: | Cutler; Paul H.; (State College, PA) |
| Correspondence Address: | KENYON & KENYON LLP ONE BROADWAY NEW YORK NY 10004 US |
| Serial No.: | 157842 |
| Series Code: | 12 |
| Filed: | June 13, 2008 |
| Current U.S. Class: | 136/256 |
| Class at Publication: | 136/256 |
| International Class: | H01L 31/00 20060101 H01L031/00 |
1. A device for receiving and converting incident radiation into DC current, the device comprising:a transparent conductor; at least one point-contact diode, the at least one point-contact diode having a nanowire providing a receiving antenna function and a rectification function; a thin insulating layer, situated between the transparent conductor and the nanowire; and a point-contact junction, at which the nanowire contacts the thin insulting layer.
1-Solar Cell 2-Solar Radiation 3-Transparent Cover 4-Metal Electrode 5-Thin Insulating Layer 6-mCNT Rectifying Antenna
7-Contact Area 8-Sharp Edge 9-High Frequency Diode
