TY - JOUR

T1 - Phononic, photonic and excitonic properties of ∼5 nm diameter aligned CdSe nanowires

AU - Poborchii, Vladimir V.

AU - Shklyaev, Alexander A.

AU - Fokin, Alexander V.

N1 - Сведения о финансировании Финансирующий спонсор Номер финансирования Russian Science Foundation 19–72–30023

PY - 2025/2

Y1 - 2025/2

N2 - The first work on quantum-sized CdSe nanowires (NWs) was made with NWs encapsulated in chrysotile asbestos nanotubes (asb-CdSe-NWs) in 1997. However, asb-CdSe-NWs remain under-investigated compared to widely-known solution-based CdSe NWs. Here, we study ∼5 nm diameter asb-CdSe-NWs aligned along their c-axis. Polarized optical absorption, Raman and photoluminescence spectra (OAS, RS and PLS) of asb-CdSe-NWs are examined. All spectra display a high anisotropy mainly associated with the anisotropic nearly cylindrical shape of NWs and dielectric contrast between NWs and asbestos, NW-light interaction being strong for the E//c and weak for E⊥c light polarizations. Asb-CdSe-NW E//c OAS shows ∼1.93 eV and ∼2.38 eV bands of excitonic transitions between size-quantized electronic states. RS display strong longitudinal-optical-phonon band with a weak surface-mode shoulder resonantly enhanced at the excitation wavelength corresponding to the ∼2.38 eV absorption band related to the 1Π1/2→1Πe transition. Acoustic radial breathing mode is observed at ∼14 cm−1. Low-excitation PLS show polarized exciton emission band at ∼1.883 eV while high-excitation PLS display ∼1.836 eV biexciton emission band. The ∼47 meV biexciton binding energy is enhanced due to the low-permittivity environment. Our asb-CdSe-NW results make an important complementary contribution to the studies of CdSe NWs fabricated by a variety of different techniques.

AB - The first work on quantum-sized CdSe nanowires (NWs) was made with NWs encapsulated in chrysotile asbestos nanotubes (asb-CdSe-NWs) in 1997. However, asb-CdSe-NWs remain under-investigated compared to widely-known solution-based CdSe NWs. Here, we study ∼5 nm diameter asb-CdSe-NWs aligned along their c-axis. Polarized optical absorption, Raman and photoluminescence spectra (OAS, RS and PLS) of asb-CdSe-NWs are examined. All spectra display a high anisotropy mainly associated with the anisotropic nearly cylindrical shape of NWs and dielectric contrast between NWs and asbestos, NW-light interaction being strong for the E//c and weak for E⊥c light polarizations. Asb-CdSe-NW E//c OAS shows ∼1.93 eV and ∼2.38 eV bands of excitonic transitions between size-quantized electronic states. RS display strong longitudinal-optical-phonon band with a weak surface-mode shoulder resonantly enhanced at the excitation wavelength corresponding to the ∼2.38 eV absorption band related to the 1Π1/2→1Πe transition. Acoustic radial breathing mode is observed at ∼14 cm−1. Low-excitation PLS show polarized exciton emission band at ∼1.883 eV while high-excitation PLS display ∼1.836 eV biexciton emission band. The ∼47 meV biexciton binding energy is enhanced due to the low-permittivity environment. Our asb-CdSe-NW results make an important complementary contribution to the studies of CdSe NWs fabricated by a variety of different techniques.

KW - CdSe nanowires

KW - Exciton

KW - Phononics

KW - Photonics

KW - asbestos nanotubes

UR - https://www.mendeley.com/catalogue/e98e2aca-6f00-3a05-9235-159bfe99d0c6/

UR - https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85207690594&origin=inward

U2 - 10.1016/j.jpcs.2024.112424

DO - 10.1016/j.jpcs.2024.112424

M3 - Article

VL - 197

JO - Journal of Physics and Chemistry of Solids

JF - Journal of Physics and Chemistry of Solids

SN - 1879-2553

M1 - 112424

ER -