Post by williamplayer on Jan 13, 2014 14:25:46 GMT
2D Materials and Devices beyond Graphene
Background:
Following the isolation of Graphene, a treasure trove of 2D layers have been successfully prepared, whose properties range from insulating (2D BN) to semiconducting (2D MoS2), with direct or indirect band-gap depending on the exact number of atomic layers. These new 2D materials not only complement Graphene, which is basically a conductor, but also, being 2D in nature without dangling bonds, minimally strain or otherwise perturb each other. Following the successful exploitation of thin- film hetero-structures over the past four decades, hetero-structures made of different 2D materials may enable a wide range of unique devices with unprecedented performance characteristics for electronic, photonic, sensing, structural, thermal and energy applications. For example, high-speed transistors that consume little power, optical detectors of extremely low noise, and structural layers with extremely high thermoelectric coefficients may be fabricated on flexible substrates. Multi-function devices for spintronics and quantum computing are also envisioned. However, although limited success for growing 2D BN on Graphene has been demonstrated, the weak van der Waals interaction between 2D layers makes it very challenging to grow one 2D material on top of another. It will take many years to develop growth techniques, whether van der Waals epitaxy or other techniques, for large-area 2D hetero-structures typically required for device fabrication on the commercial scale. In addition, there is little knowledge about properties derived from predictive modeling capabilities of 2D hetero-structures. Many of these challenges were discussed in a recent NSF/AFOSR workshop of the same name as this initiative.
Read Full Article: www.wpafb.af.mil/library/factsheets/factsheet.asp?id=20372#anchor1
Background:
Following the isolation of Graphene, a treasure trove of 2D layers have been successfully prepared, whose properties range from insulating (2D BN) to semiconducting (2D MoS2), with direct or indirect band-gap depending on the exact number of atomic layers. These new 2D materials not only complement Graphene, which is basically a conductor, but also, being 2D in nature without dangling bonds, minimally strain or otherwise perturb each other. Following the successful exploitation of thin- film hetero-structures over the past four decades, hetero-structures made of different 2D materials may enable a wide range of unique devices with unprecedented performance characteristics for electronic, photonic, sensing, structural, thermal and energy applications. For example, high-speed transistors that consume little power, optical detectors of extremely low noise, and structural layers with extremely high thermoelectric coefficients may be fabricated on flexible substrates. Multi-function devices for spintronics and quantum computing are also envisioned. However, although limited success for growing 2D BN on Graphene has been demonstrated, the weak van der Waals interaction between 2D layers makes it very challenging to grow one 2D material on top of another. It will take many years to develop growth techniques, whether van der Waals epitaxy or other techniques, for large-area 2D hetero-structures typically required for device fabrication on the commercial scale. In addition, there is little knowledge about properties derived from predictive modeling capabilities of 2D hetero-structures. Many of these challenges were discussed in a recent NSF/AFOSR workshop of the same name as this initiative.
Read Full Article: www.wpafb.af.mil/library/factsheets/factsheet.asp?id=20372#anchor1