Creating Better Solar Cells
The solar community continues to make strides at creating the best solar cells possible. Here's an excerpt:
Global demand for energy is increasing by the hour as developing countries move toward industrialization. Experts estimate that by the year 2050, worldwide demand for electricity may reach 30 terawatts (TW). For perspective, one terawatt is roughly equal to the power of 1.3 billion horses.
Energy from the sun is limitless – the sun provides us 120,000 TW of power at any given instant – and it is free. But today solar energy provides only about one percent of the world’s electricity. The critical challenge is making it less expensive to convert photo-energy into usable electrical energy.
To do that, we need to find materials that absorb sunlight and convert it into electricity efficiently. In addition, we want these materials to be abundant, environmentally benign and cost-effective to fabricate into solar devices.
Researchers from around the world are working to develop solar cell technologies that are efficient and affordable. The goal is to bring the installation cost of solar electricity below US$1 per watt, compared to about $3 per watt today.
At Binghamton University’s Center for Autonomous Solar Power (CASP), we are investigating ways to make thin film solar cells using materials that are abundant in nature and nontoxic. We want to develop solar cells that are reliable, highly efficient at converting sunlight to electricity and inexpensive to manufacture. We have identified two materials that have great potential as solar absorbers: pyrite, better known as fool’s gold because of its metallic luster; and copper-zinc-tin-sulfide (CZTS).