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Displaying 126 - 150 of 1439

High-brightness lasing at submicrometer enabled by droop-free fin light-emitting diodes (LEDs)

August 14, 2020
Author(s)
Robin P. Hansen, Amit K. Agrawal, Michael Shur, Jerry Tersoff, Babak Nikoobakht, Yuqin Zong
"Efficiency droop," i.e., a decline in brightness of light-emitting diodes (LEDs) at high electrical currents, limits the performance of all commercial LEDs and has limited the output power of submicrometer LEDs and lasers to nanowatts. We present a fin p

Elucidating Charge Transport Mechanisms in Graphene Inks

August 7, 2020
Author(s)
Ana C. de Moraes1, Jan Obrzut, Vinod K. Sangwan, Julia R. Downing, Lindsay E. Chaney, Dinesh K. Patel, Randolph Elmquist, Mark C. Hersam
Solution-processed graphene inks using ethyl cellulose polymer as a binder/stabilizer were blade-coated into large area films. Systematic charge transport characterization showed graphene patterns with high mobility ( 160 cm2 V-1 s-1), low energy gap

Crystallographic Polarity Measurements in Two-Terminal GaN Nanowire Devices by Lateral Piezoresponse Force Microscopy

July 23, 2020
Author(s)
Matthew Brubaker, Alexana Roshko, Samuel Berweger, Paul T. Blanchard, Todd E. Harvey, Norman A. Sanford, Kris A. Bertness
Lateral piezoresponse force microscopy (L-PFM) is demonstrated as a reliable method for determining the crystallographic polarity of individual, dispersed GaN nanowires that were functional components in electrical test structures. In contrast to PFM

The effect of strain on tunnel barrier height in silicon quantum devices

July 13, 2020
Author(s)
Ryan Stein, Michael Stewart
Semiconductor quantum dot (QD) devices experience a modulation of the band structure at the edge of lithographically defined gates due to mechanical strain. This modulation can play a prominent role in the device behavior at low temperatures, where QD

Record Fast Polarization Switching Observed in Ferroelectric Hafnium Oxide Crossbar Arrays

July 2, 2020
Author(s)
Pragya R. Shrestha, xiao Lyu, Mengwei Si, Jason P. Campbell, Kin P. Cheung, Peide Ye
The polarization switching speed of ferroelectric (FE) hafnium zirconium oxide (HZO) is studied with the device size down to sub-μm in lateral dimension. Ultrafast measurement of transient switching current on metal-ferroelectric-metal (MFM) device with a

Anomalous accelerated negative-bias- instability (NBI) at low drain bias

June 30, 2020
Author(s)
Kin P. Cheung
We observed at very low drain bias an anomalous acceleration of Negative-bias-instability at room temperature, as if the channel temperature has been raised significantly. The channel width and channel length dependent of this acceleration suggest that in

Memory update characteristics of carbon nanotube memristors (NRAM) under circuitry-relevant operation conditions

June 30, 2020
Author(s)
Dmitry Veksler, gennadi bersuker, A W. Bushmaker, Maribeth Mason, Pragya Shrestha, Kin P. Cheung, Jason Campbell, T Rueckes, L Clevlend, H Luan, D C. Gilmer
Carbon nanotubes (CNT) resistance-change memory devices were assessed for neuromorphic applications under high frequency use conditions by employing the ultra-short (100 ps -10 ns) voltage pulse technique. Under properly selected operation conditions, CNTs

Efficient hybrid mixed-ion perovskite photovoltaics: in situ diagnostics of the roles of cesium and potassium alkali cation addition

June 19, 2020
Author(s)
Ming Chun Tang, Yuanyuan Fan, Dounya Barrit, Ruipeng Li, Hoang X. Dang, Siyuan Zhang, Timothy J. Magnanelli, Nhan V. Nguyen, Edwin J. Heilweil, Christina A. Hacker, Detlet-M Smilgies, Kui Zhao, Aram Amassian, Thomas D. Anthopoulos
Perovskite photovoltaics have made extraordinary progress in efficiency and stability in the past few years owing to process and formulation developments like antisolvent drip and mixed-cation mixed-halide compositions. Perovskite solar cells performance

Contact resistance in organic field-effect transistors: conquering the barrier

May 15, 2020
Author(s)
Matthew Waldrip, Oana Jurchescu, David J. Gundlach, Emily Bittle
Organic semiconductors have sparked significant interest due to their inherent properties as flexible, solution processible, and chemically tunable electronic materials. In the last 10 years, the improvements in charge carrier mobility in small molecule

Optimization of photoluminescence from W centers in silicon-on-insulator for waveguide-coupled sources

May 13, 2020
Author(s)
Sonia M. Buckley, Alexander N. Tait, Galan Moody, Kevin L. Silverman, Sae Woo Nam, Richard P. Mirin, Jeffrey M. Shainline, Stephen Olson, Joshua Hermann, Satyvalu Papa Rao
W centers are trigonal defects generated by self-ion implantation in silicon that exhibit photoluminescence at 1.218\textmu m. We have shown previously that they can be used in waveguide-integrated all-silicon light-emitting diode sources. Here we optimize
Displaying 126 - 150 of 1439