High-speed Cu-doped ZnS/n-Si heterojunction photodiode for enhanced UV detection


KAPLAN H. K.

Journal of Alloys and Compounds, cilt.1038, 2025 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 1038
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1016/j.jallcom.2025.182849
  • Dergi Adı: Journal of Alloys and Compounds
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, INSPEC, Metadex, Public Affairs Index, Civil Engineering Abstracts
  • Anahtar Kelimeler: High-speed photodetection, P-ZnS:Cu/n-Si heterojunction, UV photodetector, ZnS:Cu thin films
  • Bursa Uludağ Üniversitesi Adresli: Evet

Özet

Ultraviolet (UV) photodetectors are crucial for applications ranging from environmental monitoring to advanced optical systems. However, achieving both high sensitivity and fast response in the UV range remains challenging. We present a high-speed UV photodiode based on a Cu-doped ZnS thin film grown on n-Si by thermionic vacuum arc (TVA) deposition. Introducing Cu into ZnS significantly improved the film's crystallinity and induced p-type behavior in ZnS, forming a robust p–n heterojunction with the n-Si. The Cu-doped device exhibits enhanced optoelectronic performance, with a peak responsivity of approximately 149 mA/W (corresponding to an external quantum efficiency of ∼49 %) under UV illumination, as well as rapid transient response characteristics (rise time ∼6.6 µs and fall time ∼291 µs). The −3 dB bandwidth reaches about 7 kHz, demonstrating significant high-speed performance. These performance metrics are competitive with the latest state-of-the-art UV photodetectors (see Table 5), highlighting the efficacy of Cu doping and TVA fabrication in advancing ZnS-based photodiodes. Overall, the ZnS:Cu/n-Si photodiode combines high sensitivity and speed, showing potential for future UV sensing technologies and integration into next-generation UV optoelectronic systems.