Surface crystallization effects on tellurium oxide thin films for low-power complementary logic circuit applications

Van-der-Waals-structured tellurium (IV) has demonstrated its potential as a promising building block for complementary logic device due to its superior electrical and optoelectronic features. Here, we demonstrated the novel approach for developing high-performance tellurium oxide (TeOX) thin film through TeOX formation and surface crystallization (SC). The crystalline structures and chemical bindings of the TeOX surfaces were carefully engineered by time- and temperature-dependent UV-ozone treatment and ALD-grown-Al2O3-assisted crystallization. The huge enhancement of device performance was achieved in the optimized SC-TeOX transistor, especially high on–off current ratio of 2.19 × 106, which can be ascribed to the synergistic effects of TeOX formation and SC process resulting in the enlarged bandgap, strong valence band edge localization, and the improved crystallinity. The performance enhancement mechanism was systematically studied by constructing SC-TeOX transistor with different TeOX region, where the TeOX creation in both Te channel and source/drain electrode regions dramatically improved performance owing to the decreased contact resistance and enhanced charge transport. Consequently, we achieved the high-performance low-power complementary logic circuits with SC-TeOX transistors, even reaching the maximum gain of 67.9 and low static power of 0.5 nW. Thus, this work demonstrates the great potentials of SC-TeOX transistor for developing advanced low-power complementary logic circuits.