Abstract
Cu2O/TiO2/Cu2O/TiO2/Si heterojunction was synthetized by sol-gel spin coating technique, and annealed at various temperatures of 600 °C, 700 °C, 800 °C and 900 °C. The effect of these various annealing temperatures on the evolution of microstructural, optical, electrical and thermal properties of heterojunctions was investigated. By increasing the annealing temperature, the analysis showed a progressive crystallization of the specimens giving a pure rutile phase of TiO2 at 900 °C, the band gap decreased from 3.43 to 2.98 eV, the green-blue photoluminescence was doubled at 800 °C, the forward current density rose from 2 to 6 μA cm−2 and the thermal conductivity increased from 0.67 to 0.83 W m−1 K−1.
•Heterojunction Cu2O/TiO2/Cu2O/TiO2/Si synthetized by sol-gel technique, deposited by spin coater and annealed at various temperatures of 600 °C, 700 °C, 800 °C and 900 °C.•Progressive crystallization of the specimens with the annealing temperature giving a pure rutile phase of TiO2 for 900 °C temperature.•The obtained materials have volume charge density of 2–2.5 × 1014cm−3, surface charge density of 2.9–9.3 . 108cm−2, and electrical capacitance of 0.2–2.8 nF.•The band gap was decreased from 3.43 to 2.98 eV with the annealing temperature.