The effect of different rates of ultra-thin gossamer-like rGO coatings on photocatalytic performance in ZnO core-shell structures for optoelectronic applications

Kirkbinar M., DEMİR A., ALTINDAL Ş., Caliskan F.

DIAMOND AND RELATED MATERIALS, cilt.130, 2022 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 130
  • Basım Tarihi: 2022
  • Doi Numarası: 10.1016/j.diamond.2022.109435
  • Dergi Adı: DIAMOND AND RELATED MATERIALS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Chemical Abstracts Core, Communication Abstracts, INSPEC, Metadex, Civil Engineering Abstracts
  • Anahtar Kelimeler: ZnO, rGO core-shell structure, Thin film coatings, Photoelectric properties, GRAPHENE OXIDE, ELECTRICAL CHARACTERISTICS, ASSISTED SYNTHESIS, CHARGE SEPARATION, INTERFACIAL LAYER, SCHOTTKY DIODE, PHOTOLUMINESCENCE, NANOPARTICLES, FABRICATION, NANOCOMPOSITE
  • Gazi Üniversitesi Adresli: Evet

Özet

In the study, core-shell-structured Al/(ZnO:rGO)/pSi/Al photo-diodes were successfully fabricated using a sol-gel spin-coating method by varying the concentration of reduced-graphene oxide (rGO) from 1 % to 9 % (wt). The ZnO:rGO composite solution was coated on a silicon (p-Si) wafer at 1000 rpm and 300 K. Both aluminum back-ohmic and front-rectifier contacts were performed on the p-Si wafer by physical-vapor-deposition (PVD). The morphological and chemical structure of the photo-diodes were determined by using field-emission scanning electron microscopy (FE-SEM), energy dispersive spectrometry (EDS), and X-ray diffraction (XRD). The current -voltage (I-V) analysis in dark and under ultraviolet (UV, 365 nm) wavelength was utilized in detail. Basic electrical parameters, including the ideality factor (n), barrier height (BH) and series-shunt resistances (Rs, Rsh), were calculated using a variety of methods and compared to each other. The Card-Rhoderick method was used to extract energy-dependent profiles of interface traps (Nss). The core-shell-structured (ZnO-7 % rGO) photo-diode exhibited the best photocatalytic performance both in dark and under various illumination intensities (50-250 mW/cm2). The ZnO:rGO interlayer at the metal-semiconductor (M/S) interface leads to improvement of the photo-diode in respect of low-ideality factor/Nss/leakage-current and high-rectification and BH.