Toshiba's transparent Cu2O tandem solar top cell achieves 8.4% efficiency

https://techxplore.com/news/2021-12-toshiba-transparent-cu2o-tandem-solar.html

"Toshiba Corporation today announced that it has successfully raised the power conversion efficiency (PCE) of its transparent Cu2O solar cell to 8.4 percent, the world's highest level for a reported Cu2O solar cell. With the cell positioned as the top cell over a 25 percent PCE silicon cell (Cu2O-Si tandem cell), Toshiba estimates that an overall PCE of 27.4 percent can be achieved, notably above the 26.7 percent highest PCE reported for any standard silicon cell"