TY - JOUR

T1 - Photonic and phononic properties of oriented 5 nm diameter tellurium nanowires

AU - Poborchii, Vladimir V.

AU - Sachkov, Victor A.

AU - Shklyaev, Alexander A.

AU - Fokin, Alexander V.

AU - Geshev, Pavel I.

N1 - We thank V.V. Zhuravlev for assistance in the asb-Te sample fabrication, as well as O. Terasaki and N. Ohnishi for the high-resolution TEM observation of bare asbestos nanotubes. The work was partially supported by the Russian Science Foundation (Grant # 19–72–30023 ). Публикация для корректировки.

PY - 2024/2

Y1 - 2024/2

N2 - We study polarized optical absorption and Raman spectra (OAS and RS) of ∼5 nm diameter tellurium (Te) nanowires (NWs) confined in chrysotile asbestos nanotubes packed parallel to each other into nearly-perfect-hexagonal lattice. Te was encapsulated into the nanotubes from molt using ∼20 kbar pressure. Asbestos with Te NWs (asb-Te) shows a high OAS/RS anisotropy due to a strong NW-light interaction for the light polarized papallel to NWs (E//c) and a weak one for the light polarized perpendicular to NWs. Importantly, asb-Te RS display bands of confined acoustic phonons at ∼9 cm−1 and ∼23 cm−1, specific signatures of 5 nm diameter Te NWs. Density-functional-theory calculation shows agreement with the observed frequencies and flattening of NW acoustic phonon dispersions useful for thermo-electricity. Asb-Te optical phonon A1-mode Raman band displays frequency upshift compared to the bulk-Te band due to enhancement of the intrachain bonds on expense of interchain ones. Asb-Te 2nd-order RS confirm this. Surprisingly, E-modes display LO-phonon RS-activity in asb-Te instead of TO-phonon-activity in bulk-Te. We observe enhancement of the NW Raman signal compared to that of bulk Te, which is associated with the Mie-resonance-induced NW-light interaction enhancement for E//c, which is important for photonic and photo-electric applications.

AB - We study polarized optical absorption and Raman spectra (OAS and RS) of ∼5 nm diameter tellurium (Te) nanowires (NWs) confined in chrysotile asbestos nanotubes packed parallel to each other into nearly-perfect-hexagonal lattice. Te was encapsulated into the nanotubes from molt using ∼20 kbar pressure. Asbestos with Te NWs (asb-Te) shows a high OAS/RS anisotropy due to a strong NW-light interaction for the light polarized papallel to NWs (E//c) and a weak one for the light polarized perpendicular to NWs. Importantly, asb-Te RS display bands of confined acoustic phonons at ∼9 cm−1 and ∼23 cm−1, specific signatures of 5 nm diameter Te NWs. Density-functional-theory calculation shows agreement with the observed frequencies and flattening of NW acoustic phonon dispersions useful for thermo-electricity. Asb-Te optical phonon A1-mode Raman band displays frequency upshift compared to the bulk-Te band due to enhancement of the intrachain bonds on expense of interchain ones. Asb-Te 2nd-order RS confirm this. Surprisingly, E-modes display LO-phonon RS-activity in asb-Te instead of TO-phonon-activity in bulk-Te. We observe enhancement of the NW Raman signal compared to that of bulk Te, which is associated with the Mie-resonance-induced NW-light interaction enhancement for E//c, which is important for photonic and photo-electric applications.

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85181665787&origin=inward&txGid=1972da92e42aae37c3cb123940812f85

UR - https://www.mendeley.com/catalogue/24d997aa-04ac-3343-9ecb-761e7d49a8dd/

U2 - 10.1016/j.jpcs.2023.111806

DO - 10.1016/j.jpcs.2023.111806

M3 - Article

VL - 185

JO - Journal of Physics and Chemistry of Solids

JF - Journal of Physics and Chemistry of Solids

SN - 0022-3697

M1 - 111806

ER -