Bio-based Au/Silk Fibroin/p-Si/Al photodiode for enhanced photodetection and antibacterial applications
APPLIED PHYSICS A: MATERIALS SCIENCE AND PROCESSING, cilt.132, ss.1-11, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 132
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s00339-026-10052-z
- Dergi Adı: APPLIED PHYSICS A: MATERIALS SCIENCE AND PROCESSING
- Derginin Tarandığı İndeksler: Academic Search Ultimate (EBSCO), Engineering Source (EBSCO), Scopus, Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest), Aerospace Database, Science Citation Index Expanded (SCI-EXPANDED), Chemical Abstracts Core, Chimica, Compendex, INSPEC
- Sayfa Sayıları: ss.1-11
- Hakkari Üniversitesi Adresli: Evet
Özet
A bio-based Au/Silk Fibroin (SF)/p-Si/Al photodiode was successfully fabricated and systematically investigated in terms of its structural, optical, electrical, wavelength-dependent photodetection, and antibacterial properties. The silk fibroin interfacial layer was prepared using a conventional degumming–dissolution process and deposited onto the p-Si substrate by spin coating. Structural and morphological analyses confirmed the formation of a homogeneous semi-crystalline SF thin film with a thickness of approximately 162.3 nm, while UV–Vis and UPS measurements revealed a wide optical band gap of 3.32 eV together with favorable electronic energy alignment for efficient carrier transport. Compared with the reference Au/p-Si/Al diode, the incorporation of the SF interfacial layer significantly improved the electrical characteristics by reducing the ideality factor to 1.22, increasing the Schottky barrier height to 0.84 eV, and decreasing the series resistance to 576 Ω. Under different illumination intensities, the fabricated photodiode exhibited enhanced photocurrent, responsivity, specific detectivity, linear dynamic range, and stable ON/OFF switching behavior. Furthermore, wavelength-dependent measurements performed under monochromatic illumination (365–850 nm) revealed a pronounced spectral photoresponse, with the highest photocurrent, responsivity, and specific detectivity obtained in the ultraviolet region, followed by a gradual decrease toward the visible and near-infrared regions, demonstrating broadband photodetection capability. The maximum specific detectivity reached the order of 10¹³ Jones, indicating excellent signal-to-noise performance. Although the transient response times were in the order of a few seconds, the device exhibited highly stable and reproducible switching behavior, making it suitable for low-speed bio-optoelectronic sensing applications. Quantitative antibacterial analyses further demonstrated inhibition zone diameters of 15.8 ± 0.6 mm against Escherichia coli and 13.2 ± 0.5 mm against Staphylococcus aureus. These results demonstrate that the Au/Silk Fibroin/p-Si/Al photodiode is a sustainable multifunctional platform combining broadband wavelength-selective photodetection with antibacterial functionality for wearable electronics, biomedical sensors, and environmentally friendly optoelectronic applications.