Current solar cells utilize silicon to absorb solar radiation and generate electricity. Recently, a new discovery of two specific perovskites has led to a more efficient and cheaper solar cell. A tandem combination of two perovskites that absorb different aspects of the solar spectrum have been processed to generate a new solar panel. Unlike silicon, perovskites can be easily converted to sunlight-absorbing layers with very little expense. Perovskites normally absorb high energy blue photons while silicon absorbs a medium energy photon. The presence of high energy photons in sunlight is limited but the rate of energy production is much higher. For this reason, scientists have designed solar cells with both silicon and perovskites to more effectively absorb a broader spectrum of solar radiation. In fact these tandem cells are more efficient than an all perovskite cell. A normal silicon panel would have a 3.8% energy conversion efficiency. An all perovskite cell has an efficiency of 18% while a tandem cell has an efficiency of 24%. This new discovery has led to a cheaper and more effective way of solar panel utilization. With over eight times more energy produced per joule of sunlight, the renewable energy market has gained tremendous progress. More research is being done towards improving this technology. It is thought that a modified version of a perovskite can be utilized to absorb all energy photons. This way the cell can be one material that is easily converted and accessible.
SOURCE: https://www.sciencemag.org/news/2019/04/amp-solar-cells-scientists-ditch-silicon
