Annealing-free, electron-selective ohmic contacts using zirconium oxide and aluminum for n-type crystalline silicon solar cells

2024-06-15
Madbouly, Loay Akmal
Nasser, Hisham
Borra, Mona Zolfaghari
Çiftpınar, Emine Hande
Altiner, Gokhan
Aliefendioglu, Atescan
Canar, Hasan Huseyin
Turan, Raşit
Ünalan, Hüsnü Emrah
The challenge of Fermi-level pinning significantly complicates the establishment of Ohmic, low-resistance contacts for lightly doped n-type crystalline silicon (c-Si), a critical requirement for economically feasible device development. In this novel study, we present an innovative approach by introducing an ultra-thin zirconium oxide (ZrOx) film to achieve an Ohmic contact in n-type c-Si. The ZrOx films are deposited through e-beam evaporation at room temperature, and their properties are characterized using spectroscopic ellipsometry (SE), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and contact resistivity (ρc) measurements. Our investigation unveiled a pronounced dependence of the contact resistivity on the thickness of the ZrOx layer, with the lowest ρc value of 22 mΩ cm2 achieved with an ultrathin 1 nm ZrOx film. To demonstrate our study's feasibility, we applied ZrOx as an electron-selective rear-side contact layer in a lightly doped n-type c-Si solar cell with a boron-diffused emitter on the front side. This yielded a photovoltaic conversion efficiency (PCE) of 16% and a notable fill factor (FF) exceeding 79%. These findings clearly emphasized the significant promise of ZrOx as an emerging and highly effective electron-selective contact layer for lightly doped n-type c-Si devices.
Materials Science in Semiconductor Processing
Citation Formats
L. A. Madbouly et al., “Annealing-free, electron-selective ohmic contacts using zirconium oxide and aluminum for n-type crystalline silicon solar cells,” Materials Science in Semiconductor Processing, vol. 176, pp. 0–0, 2024, Accessed: 00, 2024. [Online]. Available: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85187224373&origin=inward.