A Monoclinic V1-x-yTixRuyO2 Thin Film with Enhanced Thermal-Sensitive Performance

Yatao Li,Xin Zhou,Shiyang Xu,Kai Yuan,Deen Gu,Yadong Jiang

doi:10.1186/s11671-020-03322-z

Abstract

Preparing the thermal-sensitive thin films with high temperature coefficient of resistance (TCR) and low resistivity by a highly compatible process is favorable for increasing the sensitivity of microbolometers with small pixels. Here, we report an effective and process-compatible approach for preparing V1-x-yTixRuyO2 thermal-sensitive thin films with monoclinic structure, high TCR, and low resistivity through a reactive sputtering process followed by annealing in oxygen atmosphere at 400 °C. X-ray photoelectron spectroscopy demonstrates that Ti4+ and Ru4+ ions are combined into VO2. X-ray diffraction, Raman spectroscopy, and transmission electron microscopy reveal that V1-x-yTixRuyO2 thin films have a monoclinic lattice structure as undoped VO2. But V1-x-yTixRuyO2 thin films exhibit no-SMT feature from room temperature (RT) to 106 °C due to the pinning effect of high-concentration Ti in monoclinic lattice. Moreover, RT resistivity of the V0.8163Ti0.165Ru0.0187O2 thin film is only one-eighth of undoped VO2 thin film, and its TCR is as high as 3.47%/°C.

Highlights

Microbolometers have been widely applied in civil and military fields
We demonstrate a high-performance monoclinic V1-x-yTixRuyO2 thermal-sensitive thin film through a semiconductor-to-metal transition (SMT)-inhibition strategy by means of introducing Ti and Ru ions into Vanadium dioxide (VO2) thin films
V1-x-yTixRuyO2 thin films have been prepared by a reactively magnetron co-sputtering process followed by annealing at 400 °C

Summary

Introduction

One of the important development trends is reducing the pixel size in order to reduce product cost and increase the detection range [1]. Improving the micro-electromechanical system (MEMS) manufacturing process to optimize the filling factor, absorption coefficient, thermal conductivity, and other key factors can effectively enhance the sensitivity, but this approach is coming to its limit [1]. Another effective way is using better thermal-sensitive materials [2]. As a widely used thermal-sensitive material, VOx with a relatively low resistivity in the range of 0.1–5.0 Ω·cm has a TCR of about 2%/°C at room temperature [3].

Methods

Results

Conclusion