Scientists demonstrate effect of confining dielectrics on semiconductor nanowire co...(previous theoretical prediction. Fu...)

Further, detailed calculations using finite element method, carried out by graduate student Alexi Girgis of WPI, were used to iteratively solve the wave functions and energies of conduction electrons and accounted for the induced surface charges. The inverse radius dependence turned out to be a good approximation only for certain range of wire sizes.

"Our key finding was that devices made with nanowires, such as nanowire field-effect transistors, require imaginative design of the materials, the surrounding dielectric, and the operating voltage bias to take into account dielectric confinement effects," says Narayanamurti.

Previously, the effects of dielectric confinement have been investigated theoretically for the role they play in defining the optical properties of nanostructures, such as exciton binding energies, while the impact on electrical characteristics has largely been neglected partly due to the misconception that the relevant length scale still falls into the "classical" regime.

The present work opens up the general prospect of dielectric confinement engineering, or a way to exploit and optimize the performance of nanowire electronic and optoelectronic devices.

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