High-Performance Transparent Electron-Selective Contact for Crystalline Silicon Solar Cells

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 (rho c) of 56.0 m ohm 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. A high-performance transparent electron-selective passivating contact for crystalline silicon solar cells is reported. By the implementation of the (intrinsic hydrogenated amorphous silicon) /magnesium oxide/aluminium doped zinc oxide front contact, a high power conversion efficiency of 23.3% is achieved on silicon heterojunction solar cells. This work expands the pool of available metal compound-based passivating contacts for crystalline silicon solar cells. image