Multi-walled carbon nanotubes based near-infrared radiation source

摘要

Emerging Near-InfraRed (NIR) spectroscopic applications such as biomedical, agrofood, health & beauty and in-line industrial applications require compact and low-cost miniaturized spectrometers. One of the main elements for such devices is the wideband light source, which can be ultimately in the form of an integrated source. In this work, we report a Multi-Walled Carbon Nanotubes (MWCNTs) NIR source for operation with a micro-electro-mechanical system (MEMS) FTIR spectrometer. The source consists of joule micro heater machined on a highly doped silicon substrate, where the heater surrounds an active area. The micro heater is made of a platinum film sputtered on silicon with a thin titanium layer used as an adhesion layer. The chips are singulated then the MWCNTs are plotted in the active area. The SonoPlot® Microplotter II is used to plot a multi-layered 4x4 mm2 MWCNTs thin film with a laser thickness of about 1μm in the active area. A voltage difference is applied to the designated pads on the chip, allowing uniform heating of the square area containing the MWCNTs. The MEMS FTIR spectrometer is used to measure the emitted power spectral density (PSD) from the source with and without the plotting of the MWCNTs thin film. The micro-plotting of the MWCNTs over the silicon substrate improved the PSD recorded by the spectrometer. The reported results show that an engineered light source based on MWCNTs and silicon serves as a good candidate for miniaturized spectrometers.