Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China.
ACS Appl Mater Interfaces. 2023 Apr 19;15(15):19209-19219. doi: 10.1021/acsami.3c01974. Epub 2023 Apr 11.
In this paper, laser micro-cladding technology (LMC) was conducted to prepare high-temperature Pt thick film sensors in situ. The formability, microstructure, sintering mechanism, and electrical properties of the LMCed Pt thick films were first studied systematically. Results indicated that with the increase of laser power density, the sintering degree of the Pt thick film increased obviously, improving its adhesion strength and reducing its resistivity. However, when the laser power density exceeded the threshold, holes or grooves were formed in the Pt film, leading to the degeneration of its properties. A Pt thick film with good adhesion strength, excellent conductive networks, and the minimum resistivity (46 ± 2 μΩ·cm) was obtained at a laser power density of 1.37 × 10 W·cm. Then, Pt thick film temperature sensors (including Pt thermal resistance temperature (RTD) and Pt-Pt10%Rh thermocouple sensors) were conformally prepared by LMC. Their temperature-sensing performance became stable after the initial high-temperature calibration, with a linearity of 0.9985 for the RTD with a TCR of 2.46 × 10/°C (at 920 °C) and a linearity of 0.9905 for the thermocouple with a Seebeck coefficient of 9.7 μV/°C, both of which are better than that made by direct DC magnetron sputtering deposition. Therefore, this work provides a novel feasible way to conformally integrate high-performance Pt film sensors in situ.
本文采用激光微熔覆技术（LMC）原位制备高温 Pt 厚膜传感器。系统研究了 LMCed Pt 厚膜的成形性、微观结构、烧结机理和电性能。结果表明，随着激光功率密度的增加，Pt 厚膜的烧结程度明显提高，从而提高了其结合强度，降低了电阻率。然而，当激光功率密度超过阈值时，Pt 膜中会形成孔或沟槽，导致其性能退化。在激光功率密度为 1.37×10^5 W·cm^-2 时，获得了结合强度好、导电网络优良、电阻率最小（46±2μΩ·cm）的 Pt 厚膜。然后，通过 LMC 制备了 Pt 厚膜温度传感器（包括 Pt 热敏电阻温度（RTD）和 Pt-Pt10%Rh 热电偶传感器）。在初始高温校准后，其温度感应性能变得稳定，RTD 的线性度为 0.9985（在 920°C 时 TCR 为 2.46×10^-3/°C），热电偶的线性度为 0.9905，塞贝克系数为 9.7μV/°C，均优于直接直流磁控溅射沉积的性能。因此，这项工作为原位集成高性能 Pt 薄膜传感器提供了一种新的可行方法。
