LAUSR

High‐efficiency silicon solar cells featuring doped silicon layer‐based carrier‐selective contacts suffer from optical losses due to parasitic absorption. In this work, a high‐performance electron‐selective contact with high transparency is presented, consisting of intrinsic hydrogenated amorphous silicon (a‐Si:H) passivation layer, atomic‐layer‐deposited conductive magnesium oxide (MgOx) and low‐work‐function aluminium doped zinc oxide (AZO). The a‐Si:H/MgOx/AZO stack is demonstrated to be an excellent and transparent electron‐selective contact on c‐Si, featuring a small contact resistivity (ρc) of 56.0 mΩ cm2 and a low saturation current density (J0) of 2.9 fA cm−2 simultaneously. By the implementation of the a‐Si:H/MgOx/AZO front contact, a high power conversion efficiency (PCE) of 23.3% is achieved on silicon heterojunction (SHJ) solar cells, featuring an absolute short‐circuit current density (Jsc) and PCE gain of 1.3 mA cm−2 and 1.2%, respectively, compared to the conventional phosphorus‐doped silicon layer‐based electron‐selective contact. Moreover, a state‐of‐the‐art PCE of 22.8% is obtained on c‐Si solar cells with dopant‐free asymmetric heterocontacts on both sides, featuring an a‐Si:H/MgOx/AZO front contact and an a‐Si:H/vanadium oxide (VOx) rear contact.