Efficient and stable perovskite–silicon two-terminal tandem solar cells

Excerpt

In the past several years, perovskite solar cells (PSCs) exhibited unexpected breakthrough and rapid evolution, and the power conversion efficiency (PCE) of single-junction PSCs has been increased significantly from 3.81 to 25.2% [1, 2], resulting from materials engineering, interface engineering, crystallization engineering, fabrication engineering, etc. [3‐5]. In the case of silicon solar cells, the record PCE is up to 26.7%, and it is very close to the theoretical Shockley–Queisser limit [2, 6]. In order to overcome the efficiency limitation of single-junction devices and reduce the cost, perovskite–silicon tandem route can be potentially used to construct more efficient solar cells via stacking complementary wide-band gap perovskite absorber and narrow-band gap silicon absorber [7]. Traditional crystalline silicon solar cells can absorb visible light and near-infrared light over the solar spectrum and convert them into electrical energy, but photons in the visible region have thermal relaxation phenomena that cause a portion of the energy to be lost in the form of thermal energy. Using tandem solar cell technology, a polycrystalline perovskite film device that can efficiently convert visible light is directly prepared on the surface of a crystalline silicon solar cell, while a silicon solar cell is only responsible for converting infrared light transmitted through the perovskite film, which would greatly enhance the PCEs over 30%. Recently, two papers published in Science reported efficient and stable perovskite–silicon two-terminal tandem solar cells [8, 9]. …