Thermal Energy Harvesting

Tunable thermal conductivity in defect engineered nanowires at low temperatures

“…InAs NWs have been studied extensively to probe their charge and spin-transport [11][12][13] . An aspect of InAs NWs that makes studying their thermal transport, hitherto little explored 14,15 , of interest is the ability to tune the density of twin defects and polytypes along its length by varying growth parameters [16][17][18][19][20] . Exploiting this control over crystal structure can help synthesize defect-engineered NWs, whose lattice has aperiodic array of twins along its length that modify phonon behavior, without significantly compromising their electrical properties 20 .…”

“…In this work we explore the κ of suspended InAs NW field effect transistors (FETs); the NWs have high density of aperiodic twins and polytypes perpendicular to their axis [16][17][18]20 . The random nature of defects suppresses κ ph (the phonon contribution to κ) resulting in reduction of thermal conductivity by 3 orders of magnitude from bulk.…”

“…Figs. 2(c) & (d) show a detailed view of the twins and polytypes [16][17][18]20 . The typical spacing of these defects is ∼3-5 nm.…”