Implementing Thermometry on Silicon Surfaces Functionalized by Lanthanide-Doped Self-Assembled Polymer Monolayers

Abstract

The thermal gradients generated at submicrometer scale by the millions of transistors contained in integrated circuits are becoming the key limiting factor for device integration in micro- and nanoelectronics. Noncontact thermometric techniques with high-spatial resolution are, thus, essential for noninvasive off-chip characterization and heat management on Si surfaces. Here, the first ratiometric luminescent molecular thermometer implemented in a self-assembled polymer monolayer functionalized Si surface is reported. The functionalization of Si surfaces with luminescent thermometers constitutes a proof-of-concept that foretells a wide range of applications in Si-based micro- and nanostructures. The thermometric functionalization of the Si surface with Tb3+ and Eu3+ complexes leads to a thermal sensitivity up to 1.43% K-1, a cycle-recycle reliability of 98.6%, and a temperature uncertainty of less than 0.3 K. The functionalized surface presents reversible bistability that can be used as an optically active molecular demultiplexer.