By David L. Chandler | MIT News Office
It’s a well-known phenomenon in electronics: Shining light on a semiconductor, such as the silicon used in computer chips and solar cells, will make it more conductive. But now researchers have discovered that in a special semiconductor, light can have the opposite effect, making the material less conductive instead.
The phenomenon …read more
Via:: MIT press office
Nature Nanotechnology 9, 768 (2014).
doi:10.1038/nnano.2014.207
Authors: Gianluca Fiori, Francesco Bonaccorso, Giuseppe Iannaccone, Tomás Palacios, Daniel Neumaier, Alan Seabaugh, Sanjay K. Banerjee & Luigi Colombo
Via:: Nature Nanotechnology
By In Soo Kim, Vinod K. Sangwan, Deep Jariwala, Joshua D. Wood, Spencer Park, Kan-Sheng Chen, Fengyuan Shi, Francisco Ruiz-Zepeda, Arturo Ponce, Miguel Jose-Yacaman, Vinayak P. Dravid, Tobin J. Marks, Mark C. Hersam, Lincoln J. Lauhon
Ultrathin transition metal dichalcogenides (TMDCs) of Mo and W show great
potential for digital electronics and optoelectronic applications. Whereas
early studies were limited to mechanically exfoliated flakes, the large-area
synthesis of 2D TMDCs has now been realized by chemical vapor deposition (CVD)
based on a sulfurization reaction. Since then, the optoelectronic properties of
CVD grown …read more
Via:: arXiv Material Science
By Larry Hardesty | MIT News Office
Chips that use light, rather than electricity, to move data would consume much less power — and energy efficiency is a growing concern as chips’ transistor counts rise.
Of the three chief components of optical circuits — light emitters, modulators, and detectors — emitters are the toughest to build. One promising …read more
Via:: MIT press office
By Belle Dumé Interface between two dichalcogenides could be used to fabricate transistors, LEDs and solar cells within a single atomically thin layer. …read more
Via:: Nanotechweb
Stretchable electrodes are reviewed by C. Yan and P. S. Lee on page 3443. The key innovative feature for stretchable energy storage devices is that the device is made of soft electrodes and can be deformed into various shapes without affecting the performance. The schematic illustration in the image shows …read more
Via:: Small
By Ignacio Gutiérrez Lezama, Alberto Ubaldini, Maria Longobardi, Enrico Giannini, Christoph Renner, Alexey B Kuzmenko and Alberto F Morpurgo Semiconducting transition metal dichalcogenides (TMDs) have emerged as materials that can be used to
realize two-dimensional (2D) crystals possessing rather unique transport and optical properties.
Most research has so far focused on sulfur and selenium compounds, while tellurium-based materials
have attracted little attention so far. As a first step in the investigation of Te-based
semiconducting TMDs in this context, we have studied MoTe 2 crystals with thicknesses above 4 nm,
focusing on surface transport and a quantitative determination of the gap structure. Using
ionic-liquid gated transistors, we show that ambipolar transport at the surface of the material is
reproducibly achieved, with hole and electron mobility values between …read more
Via: 2D materials
By Kai Tak Lam, Gyungseon Seol and Jing Guo
A vertical transistor based on a double gated, atomically thin heterojunction is theoretically examined. Both p-type and n-type transistor operations can be conveniently achieved by using one of the two gates as the switching gate. The transistor shows excellent saturation of output I-V characteristics due to drain-induced depletion and lack of tunneling barrier layers. The subthreshold slope could be below the thermionic limit due to band filtering as the switching mechanism. The atomically thin vertical PN heterojunction can be electrostatically modulated from a type II heterojunction to a broken bandgap alignment, which is preferred for …read more
A novel structure of tunnel field-effect transistor (FET) is introduced with the gate composed of three segments of different work functions. The tunnel current is controlled by an in channel potential barrier as well as the source-channel tunnel junction bandgap, which combines the merits of both bandgap-controlled tunnel FET and …read more