Optimisation and modification of TiO2 nanorods towards a highly efficient interfacial layer for uniformly CU2O deposition in heterojunction solar cell applications

• Main Author: Ahmad, Norazlina
• Format: Thesis
• Language: English; English; English
• Published: 2021
• Subjects: T Technology (General); TA401-492 Materials of engineering and construction. Mechanics of materials
• Online Access: http://eprints.uthm.edu.my/5526/1/24p%20NORAZLINA%20AHMAD.pdf; http://eprints.uthm.edu.my/5526/2/NORAZLINA%20AHMAD%20COPYRIGHT%20DECLARATION.pdf; http://eprints.uthm.edu.my/5526/3/NORAZLINA%20AHMAD%20WATERMARK.pdf; http://eprints.uthm.edu.my/5526/
• Institution: Universiti Tun Hussein Onn Malaysia

The deficiency of successful heterojunction solar cell development detains the future implementation of oxide-based photovoltaic devices. In the group of semiconducting compounds, titanium dioxide (TiO2) which has superior properties in solar cell development, and copper (I) oxide (Cu2O) is the best candidate that serves as an absorber layer, owing to its excellent optical properties. In this work, TiO2 with a well-aligned nanorods structure and high adhesion was synthesized on fluorinedoped tin oxide (FTO) substrate by hydrothermal method. The incorporation of Cu2O on TiO2 nanorods by electrodeposition method resulted in an inhomogeneous growth of Cu2O film attributed to a high resistivity of TiO2 film. Hydrothermal etching treatment in a highly acidic medium of hydrochloric acid (HCl) was employed to create a high efficiently interfacial layer of TiO2 with low resistivity for uniformity of Cu2O film deposition. The morphology changed, and the transmittance increased while the electrical resistivity declined, showing that the etching treatment had a substantial effect on the TiO2 thin film properties. In this study, the first fabrication of Cu2O on the etched TiO2 layer was demonstrated using the facile and easily electrodeposition method. Cu2O film was successfully deposited with high uniformity on the etched-TiO2 layer as the pyramid structure could stack perfectly on the rods layer, which is believed to improve the properties of the interfacial layer. When applied in photovoltaic solar cell, the heterojunction thin film exhibited an efficiency of 0.0138% under an irradiance of 100 mW/cm of the TiO2 film etching for 5 hours deposited with Cu2O for 90 minutes. Even though the application of Cu2O/etched-TiO2-nanorods in thin-film solar cells presents a meagre photovoltaic performance, far from the theoretical limit reports, this work could motivate other researchers to do the enhancement through intensive research for both TiO2 and Cu2O materials.