Transparent Oxide/Metal/Oxide Thin Film Heater With Integrated Resistive Temperature Sensors
Nicola Lovecchio, Valentina Di Meo, D. Caputo, A. Nascetti, A. Crescitelli, E. Esposito, G. de Cesare
Abstract
In this paper we present a device integrating on a single glass substrate a transparent heater and two resistive temperature sensors. Both heater and sensors are constituted by ITO/Au/ITO stacked film, whose thicknesses have been optimized in order to achieve at the same time good electrical conductivity (about 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> S/m) and high transparency degree (higher than 80%) in the visible region of the spectrum. A double-spiral design has been chosen for the heater in order to achieve a uniform temperature distribution on a large area. Indeed, this geometry ensures a temperature variation of ±1.4 °C in a 2.8 cm diameter circle. For the resistive temperature sensors, a distributed meander-shaped geometry ensures temperature sensitivity as high as 0.12 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{k}\pmb \Omega / ^{\circ }\text{C}$ </tex-math></inline-formula> . The proposed device shows therefore the capability to work as a large-area transparent heater introducing the possibility to perform a precise control of the substrate temperature.