{"title":"Phononic, photonic and excitonic properties of ∼5 nm diameter aligned CdSe nanowires","authors":"","doi":"10.1016/j.jpcs.2024.112424","DOIUrl":null,"url":null,"abstract":"<div><div>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 <strong>c</strong>-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 <strong><em>E</em></strong>//<strong>c</strong> and weak for <strong><em>E</em></strong>⊥<strong>c</strong> light polarizations. Asb-CdSe-NW <strong><em>E</em></strong>//<strong>c</strong> 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 1Π<sub>1/2</sub>→1Π<sub>e</sub> transition. Acoustic radial breathing mode is observed at ∼14 cm<sup>−1</sup>. 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.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":null,"pages":null},"PeriodicalIF":4.3000,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Physics and Chemistry of Solids","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022369724005596","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
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.
期刊介绍:
The Journal of Physics and Chemistry of Solids is a well-established international medium for publication of archival research in condensed matter and materials sciences. Areas of interest broadly include experimental and theoretical research on electronic, magnetic, spectroscopic and structural properties as well as the statistical mechanics and thermodynamics of materials. The focus is on gaining physical and chemical insight into the properties and potential applications of condensed matter systems.
Within the broad scope of the journal, beyond regular contributions, the editors have identified submissions in the following areas of physics and chemistry of solids to be of special current interest to the journal:
Low-dimensional systems
Exotic states of quantum electron matter including topological phases
Energy conversion and storage
Interfaces, nanoparticles and catalysts.