Thermal conductivity suppression in GaAs–AlAs core–shell nanowire arrays

Abstract

Semiconductor nanowire heterostructures have been shown to provide appealing properties for optoelectronics and solid-state energy harvesting by thermoelectrics.

Thermoelectric Characteristics of InAs Nanowire Networks Directly Grown on Flexible Plastic Substrates

“…In addition to the n-type InAs system studied here, this would allow the investigation of both p-type materials required by complementary thermoelectric generators and higher-performing n-type materials, such as InSb, which has previously been predicted to possess the highest thermoelectric power factor among the III-V compounds . Further, introducing core–shell heterostructures could offer a pathway to increased control over both the electronic and thermal transport in the network structure …”

“…11 Further, introducing core−shell heterostructures could offer a pathway to increased control over both the electronic and thermal transport in the network structure. 50…”

Core–shell nanostructures for better thermoelectrics

“…114 Several experimental and theoretical studies have shown the possibilities of producing promising thermoelectric materials in the form of core-shell nanowires. [115][116][117][118] Successful examples include Ge@Si, 114,115,119,120 Si@Ge, 121,122 GaAs@AlAs, 117 GaAs@AlGaAs, 123 Bi 2 S 3 @Bi, 116 Bi@Te, 124 Te@Bi, 125 Bi@TiO 2 , 126 multiwalled carbon nanotubes (MWCNT)@Sb 2 Te 3 , 127 Bi 2 Te 3 @MWCNT, 128 and so on. These special heterostructures show superior electronic properties and a significant reduction in thermal conductivity compared to single element nanowires.…”

Heat Transport Control and Thermal Characterization of Low-Dimensional Materials: A Review

“…For example, a strong thermal conductivity reduction was found in Si and SiGe alloy NWs with diameters of few tens of nanometers, indicating the important effect of the core-shell interface on phonon transport [54]. Juntunen et al also found up to~60% reduction of the thermal conductivity of GaAs NWs coated with AlAs shells [55]. A different study showed that the k along a single Si nanowire can be tuned (between crystalline and amorphous limits) through selective helium ion irradiation with a well-controlled dose [56].…”