Eliminating Mobility-Thickness Dependence in Transparent Conductive Oxide Layer Growth: A Critical Nucleation...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Carrier mobility is crucial for transparent conductive oxide (TCO) performance, but it typically degrades in ultrathin films.
• Existing methods struggle to produce high-quality ultrathin TCOs due to thickness-dependent deterioration.

Purpose of the Study:

• To develop a novel strategy for fabricating high-quality ultrathin TCO films with thickness-independent carrier mobility.
• To investigate a new film growth mode that suppresses scattering mechanisms in TCOs.

Main Methods:

• A critical nucleation strategy (CNS) was employed to manipulate nucleation status for specific film thicknesses.
• Cerium-doped indium oxide (ICO) films of 10, 20, and 30 nm were fabricated using CNS.
• A novel film growth mode emphasizing weakly-crystallized as-deposited films was proposed.

Main Results:

• Ultrathin ICO films (10-30 nm) fabricated via CNS exhibited significantly higher electron mobility (108-127 cm² V⁻¹ s⁻¹) compared to conventional methods.
• A 10 nm ICO film integrated into a silicon heterojunction solar cell achieved 25.16% efficiency, comparable to devices with much thicker TCO layers.
• The CNS approach demonstrated a potential 90% reduction in indium usage.

Conclusions:

• The critical nucleation strategy effectively overcomes the thickness-dependent degradation of carrier mobility in TCOs.
• The proposed film growth mode enables the fabrication of high-performance ultrathin TCOs suitable for advanced optoelectronic applications.
• This advancement holds significant promise for reducing material costs and expanding the terawatt-scale photovoltaic industry.