Development of high-performance p-type tellurium thin film transistors (TFTs) via vapor phase deposited polymer passivation

Abstract

High-performance semiconducting films which could be easily fabricated on various substrates in large scale, with sufficiently low process temperature have been studied for long time in various aspects such as soft, wearable electronics and complex circuits with extremely high density. Among various studies conducted on the TFTs, the basic unit of electronic system, p-type TFTs especially require further developments compared to n-type TFTs. Tellurium had attracted researchers’ attentions for long time as a new p-type semiconducting material with the ease of large-area fabrication and high mobility but unresolved drawbacks remained until now. Tellurium films with high mobility possess very narrow bandgap which at the same time cannot provide sufficient barrier to block undesirable charge flow and this resulted in poor switching behavior. In this study, vapor-phase-deposited, electron-donating polymer passivation was employed to modify the energy band structure of tellurium and enhance the switching property as a semiconductor. Tellurium TFTs with the electron-donating passivation layer exhibited I_on/off higher than $10^3$, hole mobility of ~12.5 $cm^2$/Vs, and clearly enhanced switching performance through the shift of threshold voltage. This simple, effective passivation method will provide possibilities in the realization of high-performance p-type TFTs which could be fabricated for industrial use and deliver various implications in next-generation semiconductor technologies.