Integrated circuits are key to modern hardware since its invention by Jack Kilby in 1958. If actual microchips are a set of electronic components on a semiconductor wafer, the same functions can be obtained using light instead of electrons. And benefits of photonic integrated circuits (PICs) are important : higher speed, lower energy loss and a greater bandwidth.
Indium phosphide (InP) is the most mature and high performance PIC platform, and NASA use it for space applications for its reliability. A way of making a PIC with InP is to grow an epitaxial material structure on the InP substrate, for example by MOCVD. In this example, the active region can be made of an InGaAsP multi-quantum well.
(a) Epitaxial structure in the active region; (b) Sideview of the active/passive interface following regrowth
Source : Zhao et al. IEEE Journal of Selected Topics in Quantum Electronics (Volume: 24 , Issue: 6 , Nov.-Dec. 2018)
Physicists at the University of Groningen have now imaged hydrogen at the titanium/titanium hydride interface with the help of a transmission electron microscope.Lire la suite
Physicists at the University of Bath have developed a flexible process allowing the synthesis in a single flow of a wide range of novel nanomaterials with various morphologies, with potential applications in areas including optics and sensors.
The nanomaterials are formed from Tungsten Disulphide – a Transition Metal Dichalcogenide (TMD) – and can be grown on insulating planar substrates without requiring a catalyst. TMDs are layered materials, and in their two-dimensional form can be considered the inorganic analogues of graphene.