Strain modulation effects on two-dimensional tellurium for advanced p-type transistor applications

Abstract

Two-dimensional p-type material, tellurium (Te), has been of particular interest owing to its extraordinary electronic, optoelectronic, and thermoelectric properties. Here, we report a promising strategy to demonstrate enhanced performance Te transistor via strain modulation effect. The compressive and tensile strains were induced to the room-temperature-sputtered Te channel layer by stacking with various metal interfacial layers, followed by the strain relaxation and deoxidization effects caused by the deposition of the aluminum oxide via atomic layer deposition process. The strain engineering mechanism was comprehensively investigated by various characterizations, and both strain modulation and deoxidization-assisted crystallinity improvement were shown to synergistically enhance the charge transport of Te transistor. As a result, the improvement in the device performance with uniformity was clearly achieved, demonstrating the carrier mobility of 12.05 cm2/V·s, the threshold voltage of 0.09 V, and the subthreshold swing of 4.34 V/decade. This further results in the stable long-term operation over 28 days and excellent electrical stability under harsh negative and positive biasing conditions. Thus, this study presents a novel strategy of strain modulation for improving the performance of Te transistor, which has great potentials for complementary-metal–oxide–semiconductor logic circuits.