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

Madbouly L. A., Nasser H., Borra M. Z., ÇİFTPINAR E. H., Altiner G., Aliefendioglu A., ...Daha Fazla

Materials Science in Semiconductor Processing, cilt.176, 2024 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 176
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1016/j.mssp.2024.108310
  • Dergi Adı: Materials Science in Semiconductor Processing
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Applied Science & Technology Source, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, Computer & Applied Sciences, INSPEC, Metadex
  • Anahtar Kelimeler: Electron selective contacts, n-type crystalline silicon, Solar cells, Zirconium oxide
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

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.