Researchers at US Rice University have developed their own perovskite solar cells using bromine and indium in addition to inorganic cesium, lead and iodide, which they claim led to an efficiency of above 12% for these cells and an open circuit voltage of 1.20 V.
The use of indium and reduction of lead helps engineer the defects in cesium-lead-iodide solar cells that affect the compound's band gap thereby improving their efficiency, claim the researchers.
They say the instability factor due to light, humidity and heat negatively impact perovskites performance but this happens because of the 'intrinsically unstable materials' themselves. Rice University developed perovskite solar cells can be made in open air, and last for months providing stability to the material with over 12% efficiency, claim the researchers.
"The highest efficiency for this material may be about 20%, and if we can get there, this can be a commercial product," explained Rice University postdoctoral researcher Jia Liang. "It has advantages over silicon-based solar cells because synthesis is very cheap, it's solution-based and easy to scale up. Basically, you just spread it on a substrate, let it dry out, and you have your solar cell."
Their research work titled Defect-Engineering-Enabled High-Efficiency All-In has been published in Advanced Materials.