High-quality ITO/Al-ZnO/n-Si heterostructures with junction engineering for improved photovoltaic performance

Chong Tong, Manjeet Kumar, Ju Hyung Yun, Joondong Kim, Sung Jin Kim

Research output: Contribution to journalArticlepeer-review


A heterostructure of Sn-doped In2O3 (ITO)/Al-doped ZnO (AZO)/n-Si was proposed and studied for photovoltaics. The top ITO worked as a transparent conducting layer for excellent optical transparency and current collection. The AZO/n-Si served as the active junction and provided the built-in potential (qVbi) for the photovoltaic devices. To achieve a higher open circuit voltage (Voc), which is the main challenge for AZO/Si heterojunctions due to the junction interfacial defects, the AZO and AZO/Si junction properties were systematically investigated. By modulating the Al doping in the AZO thin films via a dual beam co-sputtering technique, the AZO/n-Si junction quality was significantly improved with qVbi increased from 0.21 eV to 0.74 eV. As a result, the Voc of our best device was enhanced from 0.14 V to 0.42 V, with a short circuit current (Jsc) of 26.04 mA/cm2 and a conversion efficiency (Eff) of 5.03%. To our best knowledge, this is the highest Voc reported for ZnO/Si heterojunctions prepared by the sputtering method. The results confirmed the validity of our proposed structure and junction engineering approach and provided new insights and opportunities for ZnO/Si heterojunction optoelectronics.

Original languageEnglish (US)
Article number5285
JournalApplied Sciences (Switzerland)
Issue number15
StatePublished - Aug 2020


  • Al-ZnO/Si heterojunction photovoltaic
  • Built-in potential
  • Junction engineering
  • Thin film stress release

ASJC Scopus subject areas

  • Materials Science(all)
  • Instrumentation
  • Engineering(all)
  • Process Chemistry and Technology
  • Computer Science Applications
  • Fluid Flow and Transfer Processes


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