Charged Quantum Dots Increase Solar Cell Efficiency
Monday, January 23 2012With military colleagues, a trio of University at Buffalo engineers have shown that embedding charged quantum dots into photovoltaic cells can improve electrical output by enabling the cells to harvest infrared light, and by increasing the lifetime of photoelectrons.
The research team included Vladimir Mitin, Andrei Sergeev, and Nizami Vagidov from UB's electrical engineering department; Kitt Reinhardt of the Air Force Office of Scientific Research; and John Little and advanced nanofabrication expert Kimberly Sablon of the U.S. Army Research Laboratory.
Mitin, Sergeev, and Vagidov have founded a company - OPtoElectronic Nanodevices LLC. (OPEN LLC.) - to bring the innovation to the market.
The University of Buffalo researchers and their colleagues have not only successfully used embedded quantum dots to harvest infrared light; they have taken the technology a step further, employing selective doping so that quantum dots within the solar cell have a significant built-in charge, dubbed "Q-BICs."
This built-in charge is beneficial because it repels electrons, forcing them to travel around the quantum dots. Otherwise, the quantum dots create a channel of recombination for electrons, in essence "capturing" moving electrons and preventing them from contributing to electric current. The technology has the potential to increase the efficiency of solar cells up to 45 percent, according to Mitin.