Ge quantum dots on silicon for terahertz detection
Terahertz has attracted attention from both millimeter and infrared technologies. Currently, solutions consist of expensive sensor systems limiting the amount of applications. To obtain a low cost solution, one approach is to use thermistor material based on Ge on Si quantum dots on microbolometers. It has been demonstrated that SiGe monocrystalline materials have superior properties to amorphous silicon or VOx regarding the temperature coefficient of resistivity and 1/f noise. Unfortunately, the calculated critical thickness for strained SiGe material show unreasonable layer thickness for high Ge amounts. To avoid this, Ge dots instead of SiGe layers are preferred. This article focuses on optimizing the thermistor properties of Ge-dots. All samples were grown on Si (100) substrates in a temperature range of 500-650 C at 20 torr by RPCVD. They were characterized (XRD, HRSEM and AFM etc.) determining the diameter, thickness, density and uniformity. Fourier transform photoluminescence was performed to find the spatially direct (EA) and indirect (EB) bandgap transitions.
Group IV Materials for Low Cost and High Performance Bolometers
Infrared (IR) imaging has absorbed a large attention during the last two decades due to its application in both civil and military applications (Per Ericsson et al., 2010; Lapadatu et al., 2010; Sood et al., 2010). Thermal detector is presently revolutionizing the IR technology field and it is expected to expand the market for cameras. These detectors are micro-bolometers and are manufactured through micro-maching of a thermistor material. Since these detectors demand no cryogenic cooling, they provide the opportunity for producing compact, light-weight, and potentially low-cost cameras. The preferred functioning wavelength regions for these detectors are usually 8–12 ┤m due to the high transparency of the atmosphere in these regions.
Integrating Al with NiO nano honeycomb to realize an energetic material on silicon substrate
Nano energetic materials offer improved performance in energy release, ignition, and mechanical properties compared to their bulk or micro counterparts. In this study, the authors propose an approach to synthesize an Al/NiO based nano energetic material which is fully compatible with a microsystem. A two-dimensional NiO nano honeycomb is first realized by thermal oxidation of a Ni thin film deposited onto a silicon substrate by thermal evaporation. Then the NiO nano honeycomb is integrated with an Al that is deposited by thermal evaporation to realize an Al/NiO based nano energetic material. This approach has several advantages over previous investigations, such as lower ignition temperature, enhanced interfacial contact area, reduced impurities and Al oxidation, tailored dimensions, and easier integration into a microsystem to realize functional devices. The synthesized Al/NiO based nano energetic material is characterized by scanning electron microscopy, X-ray diffraction, differential thermal analysis, and differential scanning calorimetry.