Bipolar Carrier Transport of GaO x via Doping and Defect Engineering for High‐Efficiency Silicon Heterojunction Solar Cells
Year: 2025
Type: article
Abstract: Passivating contact serves as the critical enabler for fully unlocking the potential of high‐efficiency crystalline silicon (c‐Si) solar cells. Transition metal oxides (TMOs) have attracted significant attention as passivating contact layers due to their wide bandgap, tunable work function (WF), and effective surface passivation. Gallium oxide (GaO x ) exhibits ultrawide‐bandgap (≈4.8 eV), high electron mobility, and excellent field‐effect passivation due to abundant fixed charges, yet its application in passivating contacts remains unexplored. This work demonstrates tunable carrier selectivity of GaO x through ion doping for c‐Si solar cells. The Cu 2+ doping in GaO x reduces oxygen vacancies (V O ), leading to an increased WF of 5.64 eV and a decreased valence band offset with p‐Si, thereby achieving a low contact resistivity (ρ c ) of 35.09 mΩ cm 2 . In contrast, the Si 4+ doping in GaO x increases the V O , resulting in a reduced WF of 3.52 eV and a decreased conduction band offset with n‐Si, enabling a low ρ c of 24.19 mΩ cm 2 . As a result, the p‐Si/Al 2 O 3 /GaO x :Cu 2+ /Au and n‐Si/SiO 2 /GaO x :Si 4+ /Mg heterojunctions have achieved high conversion efficiencies of 21.82% and 21.49%, respectively. This work demonstrates that GaO x exhibits tunable and bipolar transport properties through doping and defect engineering, paving for the development of passivating contacts for highly efficient c‐Si solar cells.
Source: Advanced Functional Materials
Authors: Jianqiao Wang, Hang Zhou, Penghui Ren, Daoyou Guo, Yanhao Wang, Dan Liu, Songyu Li, Di Zhao, Can Cui, Shan‐Ting Zhang, Xuegong Yu, Dongdong Li, Peng Wang
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
Awards: G2857931634, G3189224250, G4751419525
OpenAlex ID: W7115011950