Editors : H.L. Tuller, J.D. Baniecki, G.J. Snyder, J.A. Malen
a1 [email protected], University of Maryland, Materials Science and Engineering, College Park, Maryland, United States
a2 [email protected], University of Maryland, Materials Science and Engineering, 1110B bldg 070, University of Maryland, College Park, Maryland, 20742, United States, 301-405-3382
We report room temperature ZT calculations for silicon and indium antimonide nanowires of varying radii. Interestingly, some systems deviate significantly from the anticipated trend of ZT vs. radius. The InSb results are particularly remarkable due to the non-monotonic relationship seen between n-type ZT and wire radius; where typically we expect to see only a decrease with increasing radius, for InSb ZT increases between 20 and 100 nm wire radii. This is thought to be due to the high level of degeneracy of subbands for larger nanowire radii. These results indicate that the monotonic relationship between ZT and wire radius observed under strong confinement conditions cannot be assumed, but must be tested on a case-by-case basis for each materials system.
(Received April 21 2010)
(Accepted May 10 2010)