Perovskite‐Based Electron‐Selective Contacts for Silicon Solar Cells

Currently, considerable efforts are devoted to developing dopant‐free carrier‐selective contacts to replace heavily doped silicon layers in crystalline silicon (c‐Si) solar cells, aiming to reduce parasitic absorption and simplify fabrication process. Herein, a thermally evaporated perovskite material, ZnTiO 3 , is demonstrated to be an excellent and highly stable dopant‐free electron‐selective contact for c‐Si solar cells. It has a low work function (4 eV), a small conduction band offset, and a large valance band offset with c‐Si. Therefore, an ohmic contact with extremely low contact resistivity (<10 mΩ cm 2 ) is achieved in the contact of c‐Si/ZnTiO 3 /Al. As a result, a power conversion efficiency over 20% is demonstrated in the c‐Si solar cell featuring ZnTiO 3 /Al as electron‐selective contacts and without advanced passivation technique, which is significantly improved compared with its counterpart (without ZnTiO 3 interlayer). Moreover, the ZnTiO 3 ‐based electron‐selective contacts exhibit exceptional long‐term stability by the test at 100 °C for 1000 h. Herein, a new cooperation mode for perovskite and c‐Si is demonstrated and a path toward developing efficient and stable c‐Si solar cells with dopant‐free electron‐selective contacts in a simple way is shown.