Selenium-alloyed tellurium oxide for amorphous p-channel transistors

Area of Science:

• Materials Science
• Semiconductor Physics
• Electronics Engineering

Background:

• Amorphous semiconductors offer cost-effective manufacturing compared to polycrystalline types, but amorphous silicon has limitations.
• High-mobility n-type amorphous metal oxides have advanced large-area electronics and displays.
• A lack of comparable p-type amorphous semiconductors hinders complementary metal-oxide-semiconductor (CMOS) technology development.

Purpose of the Study:

• To introduce a novel design strategy for high-performance amorphous p-type semiconductors.
• To demonstrate the efficacy of these new materials in stable p-channel thin-film transistors (TFTs) and complementary circuits.
• To overcome limitations in current amorphous semiconductor technology for integrated circuits.

Main Methods:

• Designed amorphous p-type semiconductors by incorporating high-mobility tellurium into an amorphous tellurium suboxide matrix.
• Utilized theoretical analysis to understand the electronic band structure and doping mechanisms.
• Employed selenium alloying to tune hole concentrations and enhance p-orbital connectivity.

Main Results:

• Achieved high-performance p-channel TFTs with field-effect hole mobility around 15 cm²/V·s and on/off current ratios of 10⁶–10⁷.
• Demonstrated wafer-scale uniformity and long-term stability under bias stress and ambient ageing.
• Theoretical analysis revealed delocalized tellurium 5p bands and shallow acceptor states enabling hole transport.

Conclusions:

• The developed tellurium-based amorphous semiconductor is a viable p-type counterpart for n-type materials.
• This represents a significant step towards commercially viable amorphous p-channel TFT technology.
• Enables low-cost, industry-compatible complementary electronics and advanced display applications.