Harnessing more than 30 years of photovoltaic research experience, a University of Arkansas engineering professor has found a way to increase sunlight-to-electricity conversion efficiency and reduce the cost of expensive materials needed for solar-cell production.
This technological breakthrough will decrease cost-per-watt production of solar electricity to a point at which it can compete with traditional, fossil-fuel-based methods.
“The problem with solar energy has been its cost per kilowatt hour,” said Hameed Naseem, professor of electrical engineering and director of the university’s Solid State Lab. “This applies to both production and consumption. With minimal further refinements, our technology will address this problem. The goal is to reduce the costs of silicon-based photovoltaics below those of traditional fossil-fuel-based methods such as coal, petroleum and natural gas.”
Most solar-cell technology is silicon based. There are three primary types of silicon solar cells, each named after the crystalline structure of the silicon used during fabrication:
• Mono-crystalline silicon has a single and continuous crystal lattice structure with practically zero defects or impurities.
• Poly-crystalline silicon, also called poly-silicon, comprises discrete grains, or crystals, of mono-crystalline silicon that create regions of highly uniform crystal structures separated by grain boundaries.
• Amorphous silicon is an entirely non-crystalline form of silicon that can be thought of as grains the size of the individual atoms.
Many commercialized solar cells incorporate amorphous silicon and poly-silicon, which have acceptable conversion efficiency and cost much less than mono-crystalline silicon.
The process developed by Naseem, known as topdown aluminum-induced crystallization, creates poly-silicon with crystal grains 30 times larger than grains currently produced in the photovoltaic industry. Standard poly-silicon contains grains of 0.5 to 1 micrometer, which is one-100th the diameter of a human hair. Naseem’s process yielded a grain size up to 150 micrometers, which is important because the performance of a photovoltaic device is limited primarily by defects at the boundaries of crystal grains. Increasing the size of crystal grains decreases the number of boundaries.
Traditional processing of silicon-based cells requires a heating temperature of 1,000 degrees Celsius to cause the silicon to reach a crystalline state. Naseem’s method of converting amorphous silicon into poly-silicon can be done at temperatures between 100 and 300 degrees Celsius, which saves time, materials and energy.
Naseem’s current and former students work with their teacher to test and refine the technology. Douglas Hutchings, a recent doctoral graduate of electrical engineering, partnered with Naseem and students in the Sam M. Walton College of Business to start a company, Silicon Solar Solutions LLC, which holds the licenses from the university to five patents on which the technology is based. In addition to testing and refining, the company owners plan to market the technology and identify manufacturers who are interested in integrating it into their production facilities.
Naseem and the engineers at Silicon Solar Solutions have already produced prototype solar cells that meet or exceed some performance metrics of cells made by major manufacturers. These laboratory results are competitive with commercially available solar cells and indicate the potential of Silicon Solar Solutions’ less expensive process, Hutchings said.
“Although cost-per-kilowatt hour has been the primary impediment to growth and development of solar power, this reality can be influenced by factors other than technological innovations that reduce costs,” Naseem said. “Consumer demand is one factor. As more people become aware of the problems associated with greenhouse-gas emissions, the demand for sources of clean energy goes up. This awareness and demand pressure government to invest in alternative sources of energy. This is where we are now. Now is a good time to develop solar. I predict it will take off and become a prolific and essential contributor to the nation’s power grid.”CONTACTS:
Matt McGowan | Newswise Science News
Supersonic waves may help electronics beat the heat
18.05.2018 | DOE/Oak Ridge National Laboratory
Researchers control the properties of graphene transistors using pressure
17.05.2018 | Columbia University
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.
Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...
A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.
Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
18.05.2018 | Power and Electrical Engineering
18.05.2018 | Information Technology
18.05.2018 | Information Technology