Printable Single-Unit-Cell-Thick Transparent Zinc-Doped Indium Oxides with Efficient Electron Transport Properties

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Ultrathin transparent conductive oxides (TCOs) are crucial for transparent electronics.
• Indium oxide (In2O3) doped with post-transition metals offers good optical and electrical properties.
• Electron transport in ultrathin TCOs often degrades compared to bulk materials.

Purpose of the Study:

• To investigate transition-metal dopants in ultrathin indium oxide (In2O3) down to the single-unit-cell limit.
• To improve electron transport properties in ultrathin TCOs.
• To explore potential for high-performance flexible transparent electronics.

Main Methods:

• Utilized a low-temperature liquid metal printing technique for large-area fabrication.
• Incorporated zinc (Zn) dopants into the In2O3 rhombohedral crystal structure.
• Optimized Zn doping levels to achieve quasimetallic transition.

Main Results:

• Achieved ultrathin In2O3 films down to the single-unit-cell thickness.
• Maintained over 98% optical transmittance.
• Obtained an electron field-effect mobility of up to 87 cm² V⁻¹ s⁻¹ and conductivity in the sub-kΩ⁻¹ cm⁻¹ range with optimized Zn doping.

Conclusions:

• Optimized Zn doping in ultrathin In2O3 significantly enhances electron transport properties.
• The developed ultrathin TCOs exhibit superior performance compared to existing materials.
• This research opens avenues for advanced flexible transparent electronic devices.