Addressing the Conflict between Mobility and Stability in Oxide Thin-film Transistors

Area of Science:

• Materials Science
• Electronics Engineering

Background:

• Amorphous oxide semiconductor thin-film transistors (AOS TFTs) are crucial for modern displays.
• Achieving high carrier mobility alongside excellent operational stability in AOS TFTs remains a significant challenge.

Purpose of the Study:

• To address the mobility-stability conflict in AOS TFTs.
• To develop a novel bilayer structure for enhanced transistor performance.

Main Methods:

• Investigated carrier transport/relaxation bilayer stacked AOS TFTs.
• Utilized amorphous In-rich InSnZnO for the charge transport layer (CTL).
• Employed Praseodymium-doped InSnZnO for the charge relaxation layer (CRL) and femtosecond transient absorption spectroscopy.

Main Results:

• The CTL exhibited favorable structural properties for charge transport.
• The CRL effectively reduced photoelectron lifetime.
• Achieved ultrahigh mobility (75.5 cm² V^-1 s^-1 ) with minimal voltage shifts under stress (-1.64/0.76 V).

Conclusions:

• The proposed bilayer design successfully resolves the mobility-stability trade-off in AOS TFTs.
• This approach offers a promising pathway for high-performance displays.
• Optimized CTL and CRL structures are key to device performance.