Synergetic substrate and additive engineering for over 30%-efficient perovskite-Si tandem solar cells

Synergetic substrate and additive engineering for over 30%-efficient perovskite-Si tandem solar cellsUsing pFBPA as an additive for solution-processed perovskites significantly suppresses non-radiative recombination.However, it simultaneously deteriorates the film quality, limiting the performance gains.Using dielectric nanoparticles underneath, the film quality can be greatly improved and the gains can be maximized.The nanoparticles also enable the use of Me-4PACz as a hole transport layer, which further improves the performance.Combined with a durable Si cell, a certified power conversion efficiency of 30.9% is achieved for a perovskite-Si tandem device.