New efficiency record achieved by tandem solar cell

• An R&D team from HZB has established a new record for tandem silicon/perovskite solar cells. The cell measured 1 sq cm has achieved 29.15 percent conversion efficiency. The researchers state that the new record of 30 percent is on the way. The achievement has been approved by the Fraunhofer Institute for Solar Energy Systems.

In order to achieve the new record, the scientists have improved a few layers of a solar device. Both intermediate layers have been optimized and a separate electrode contacting layer has been created. 

Perovskite composition has also been optimized. This has made the device more stable and has balanced the cells. Thanks to the improved Si oxide layer, optical coupling between the cells has become stronger.

Even though the record-setting cell has an area as tiny as 1 sq cm and has been made in a lab, the scientists claim it can be scaled up by means of vacuum deposition.

The previous record set up by Helmholtz Center for Materials and Energy for Si/PS cells had been 25.5 percent. A little more than a year ago, it was broken by a device with 28-percent efficiency, created by Oxford PV.

The team is now inclined to exceed 30-percent efficiency and come closer to 35 percent.