Selenium alloyed tellurium oxide for amorphous p-channel transistors

Abstract

Compared to polycrystalline semiconductors, amorphous semiconductors offer inherent cost-effective, simplicity, and uniform manufacturing. Traditional amorphous hydrogenated Si falls short in electrical properties, necessitating the exploration of new materials. The creation of high-mobility amorphous n-type metal oxides, such as a-InGaZnO¹, and their integration into thin-film transistors (TFTs) have propelled advancements in modern large-area electronics and new-generation displays^2–8. However, finding comparable p-type counterparts poses significant challenges, impeding the progress of complementary metal-oxide-semiconductor (CMOS) technology and integrated circuits^9–11. Here, we introduce a pioneering design strategy for amorphous p-type semiconductors, incorporating high-mobility tellurium within an amorphous tellurium sub-oxide matrix, and demonstrate its utility in high-performance, stable p-channel TFTs, and complementary circuits. Theoretical analysis unveils a delocalised valence band from tellurium 5p bands with shallow acceptor states, enabling excess hole doping and transport. Selenium alloying suppresses hole concentrations and facilitates the p orbital connectivity, realising high-performance p-channel TFTs with an average field-effect hole mobility of ~15 cm² V⁻¹ s⁻¹ and on/off current ratios of 10⁶ ~ 10⁷, along with wafer-scale uniformity and long-term stabilities under bias stress and ambient aging. This study represents a crucial stride towards establishing commercially viable amorphous p-channel TFT technology and complementary electronics in a low-cost and industry-compatible manner.