Development of homogenous n-TiO2/ZnO bilayer/p-Cu2O heterostructure thin film

• Published in: Journal of sol-gel science and technology Vol. 100; no. 2; pp. 224 - 231
• Main Authors: Arifin, Nurliyana Mohamad, Mohamad, Fariza, Hussin, Rosniza, Ismail, Anis Zafirah Mohd, Ramli, Shazleen Ahmad, Ahmad, Norazlina, Nor, Nik Hisyamudin Muhd, Sahdan, Mohd Zainizan, Zain, Mohd Zamzuri Mohammad, Izaki, Masanobu
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.11.2021; Springer Nature B.V
• Subjects: Absorption; Atomic force microscopy; Atomic properties; Bilayers; Ceramics; Chemistry and Materials Science; Coated electrodes; Composites; Copper oxides; Electrodeposition; Electron mobility; Field emission microscopy; Glass; Heterojunctions; Heterostructures; Inorganic Chemistry; Materials Science; Metal oxide semiconductors; Nanotechnology; Natural Materials; Optical and Electronic Materials; Optical properties; Original Paper: Functional coatings; Photovoltaic cells; Semiconductor materials; Sol-gel processes; Solar cells; Spectrum analysis; Spin coating; Substrates; Thin films; thin films and membranes (including deposition techniques); Titanium dioxide; Zinc oxide; Sol–gel spin coating; Cu; Homogenous p-n heterojunction; O-based heterostructure; Electrodeposition; Metal oxide semiconductor; TiO; ZnO bilayer
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-021-05650-7

Metal oxide semiconductor materials have shown a great potential in the fabrication of heterojunction thin film due to its improved properties for photovolatic mechanism in solar cell application. In this work, p-(111)-Cu 2 O based heterostructure was successfully developed with uniformity and highly oriented n-TiO 2 /(002)-ZnO bilayer thin film in order to overcome improper electron mobility between the heterointerface of n and p-type layer by optimizing several properties. n-TiO 2 /ZnO bilayer acts as window layer deposited on FTO substrate by using sol–gel spin coating method. The crystallize size and transmittance spectrum of n-TiO 2 thin film was improved after n-ZnO was coated onto TiO 2 thin film. Meanwhile, cyclic voltammetry (CV) measurement was carried out and potential deposition of −0.4 V vs Ag/Cl at 40 °C was acquired. p-Cu 2 O which acts as absorbing layer was deposited onto n-TiO 2 /ZnO bilayer by using electrodeposition technique. The successful fabrication of n- TiO 2 /ZnO/p- Cu 2 O heterostructure were confirmed by the existence of all peaks on the XRD spectrum. Two strong absorption edges observed and the merged shape of p-Cu 2 O grain with other layer leads to the surface flatness improvement. The optical energies of n-TiO 2 /ZnO bilayer and p-Cu 2 O thin film are estimated as 3.15 and 1.75 eV, respectively. The structural, morphological, optical, and topological properties of thin films were characterized using X-ray diffraction, Field emission-scanning electron microscope, Ultraviolet–visible spectroscopy, and Atomic force microscopy, respectively. Highlight n-TiO 2 /ZnO bilayer thin film and p-Cu 2 O thin film was fabricated by using sol–gel spin coating and electrodeposition method, respectively. The successful fabrication of n-TiO 2 /ZnO/p-Cu 2 O heterostructure were confirmed due to formation of p-(111)-Cu 2 O layer onto continuous and highly oriented-n-TiO 2 /(002)-ZnO bilayer thin film. Two strong absorption edges observed and the optical energies of n-TiO 2 /ZnO bilayer and p-Cu 2 O thin film were estimated as 3.15 and 1.75 eV, respectively.