One-Step Laser-Induced Oxidation and Doping for Tailored p-Type Conversion of Al-Doped TiO₂

Area of Science:

• Materials Science
• Semiconductor Physics
• Nanotechnology

Background:

• The integration of metal oxide semiconductors into complementary metal-oxide-semiconductor (CMOS) technology is hindered by the predominant n-type conductivity, necessitating the development of p-type alternatives.
• Titanium dioxide (TiO₂) is a widely studied n-type semiconductor, but achieving p-type conductivity in TiO₂ remains a significant challenge for balanced electronic device operation.

Purpose of the Study:

• To investigate the semiconducting type conversion of titanium dioxide (TiO₂) from n-type to p-type.
• To develop a facile and efficient method for fabricating p-type TiO₂ suitable for CMOS technology and advanced electronic applications.

Main Methods:

• Utilized laser-assisted oxidation and doping integration to achieve simultaneous TiO₂ formation and aluminum (Al) doping in a single step.
• Investigated the diffusion of Al cations into the TiO₂ lattice under specific laser power thresholds, leading to the substitution of Ti⁴⁺ with Al³⁺.
• Employed X-ray Photoelectron Spectroscopy (XPS) and Energy Dispersive Spectroscopy Transmission Electron Microscopy (EDS-TEM) to confirm TiO₂ formation and Al dopant incorporation.

Main Results:

• Demonstrated that aluminum doping converts the intrinsic n-type conductivity of TiO₂ to p-type by substituting Ti⁴⁺ with Al³⁺ ions.
• Confirmed the successful formation of TiO₂ and the incorporation of Al dopants using advanced spectroscopic and microscopic techniques.
• Fabricated laser-oxidized Al-doped TiO₂ thin-film transistors exhibiting improved hole current and enhanced photostability.

Conclusions:

• Laser-induced Al doping provides an effective method for converting n-type TiO₂ to p-type.
• The developed fabrication technique is simple, efficient, and controllable, making it suitable for CMOS technology and the development of advanced electronic devices.