TeO₂: A Prospective High‐k Dielectric

Abstract

Herein, high‐k dielectric behavior of TeO2 thin films is investigated. The films are prepared using pulsed laser deposition on indium tin oxide (ITO)–glass substrates. Increasing the growth temperature has improved the surface roughness, transparency, and bandgap of the films. Films grown at 500 °C display nanocrystalline nature which is reflected in the increase of bandgap to 4.7 eV and is higher than the bulk value of α‐TeO2 (3.7 eV). The nanocrystalline TeO2 films in the metal–insulator–metal configuration show a stable high permittivity of ≈19 with low leakage current (J < 1 × 10−7 A cm−2) and good voltage stability (α = 509 ppm V−2). Field‐effect modulation is observed in the metal–oxide–semiconductor stack configuration with tellurium as a semiconductor. The study suggests nanocrystalline TeO2 as a low‐temperature processable high‐k material with high transparency for transistor applications.

Formation-free resistive switching in nanocrystalline tellurium oxide

“…β-TeO 2 is a naturally occurring stable polymorph form with a layered structure of weakly bonded sheets while at the same time, it is challenging to synthesize compared to other phases like α-TeO 2 and γ-TeO 2 at ambient pressure due to its narrow temperature window of formation which is below the melting point of parent tellurium. Recent approaches like surface oxidation and controlled layer thinning have successfully displayed the formation of β-TeO 2 [14,15]. These works reveal exceptionally unique properties like high carrier mobility, high luminescent nature, dynamic and thermal stability annotating it as a promising material for power electronic, opto-electronic and photonic applications [16].…”