In this paper the dependence of structural properties of the quaternary CuIn1-xGaxSe2 films with tetragonal structure on the Ga content has been systematically investigated by Raman scattering and x-ray diffraction sp...In this paper the dependence of structural properties of the quaternary CuIn1-xGaxSe2 films with tetragonal structure on the Ga content has been systematically investigated by Raman scattering and x-ray diffraction spectra. The shift of the dominant A1 mode, unlike the lattice constants, does not follow the linear Vegard law with increasing Ga content x, whereas exhibits approximately polynomial change from 174 cm^-1 for CuInSe2 to 185 cm^-1 for CuGaSe2. Such behaviour should be indicative of presence of the asymmetric distribution of Ga and In on a microscopic scale in the films, due to Ga addition. The changes in the tetragonal distortion η lead to a significant variation in the anion displacement parameter U, which should be responsible for the evolution of bond parameters and resultant Raman bands with x.展开更多
Interface between metallic nanoparticles and dielectric silicon substrate can strongly confine electromagnetic field(EM-field)through its localized surface plasmons,together contributing great surface-enhanced Raman s...Interface between metallic nanoparticles and dielectric silicon substrate can strongly confine electromagnetic field(EM-field)through its localized surface plasmons,together contributing great surface-enhanced Raman scattering(SERS)enhancement.Typically,silicon-based nanohybrids(metallic nanoparticles in situ grown on silicon substrate)have been widely employed as SERS-active substrates in sensing platforms for the detection of chemical and biological analytes.Silicon-based nanohybrids with surface plasmons allow amplifying Raman signals that associate molecular binding events by several orders of magnitude.Together with interfacial architectures for the specific binding of target analyte on the silicon-based nanohy-brid surface,silicon-based nanohybrid-enhanced Raman scattering represents a promising method for increasing reliability and sensitivity.This re-view affords a presentation to the basics of SERS enhancement of silicon-based nanohybrid,illustrates current advances in controllable synthesis of silicon-based nanohybrid substrates,and outlines current implementations to sensors for reliable detection of ultralow amounts of analytes.展开更多
基金Project supported by China Postdoctoral Science Foundation （Grant No 2005037539）, and the National High-Tech Research and Development Programm of China （Grant No 2004AA513020）. Acknowledgments 0ne of the authors （Xu Chuan-Ming） gratefully acknowledges Professor Xu Cun-Yi from the Structure Research Laboratory of Chinese Academy of Sciences for the sample measurements.
文摘In this paper the dependence of structural properties of the quaternary CuIn1-xGaxSe2 films with tetragonal structure on the Ga content has been systematically investigated by Raman scattering and x-ray diffraction spectra. The shift of the dominant A1 mode, unlike the lattice constants, does not follow the linear Vegard law with increasing Ga content x, whereas exhibits approximately polynomial change from 174 cm^-1 for CuInSe2 to 185 cm^-1 for CuGaSe2. Such behaviour should be indicative of presence of the asymmetric distribution of Ga and In on a microscopic scale in the films, due to Ga addition. The changes in the tetragonal distortion η lead to a significant variation in the anion displacement parameter U, which should be responsible for the evolution of bond parameters and resultant Raman bands with x.
基金The authors acknowledge financial support from the National Natural Science Foundation of China(Nos.21825402 and 22074101)the Natural Science Foundation of Jiangsu Province of China(Nos.BK20191417 and BK20200851)+1 种基金the China Postdoctoral Science Foundation(No.2021M692347)the Program for Jiangsu Specially-Appointed Professors to the Prof.Yao He,aproject funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),111 Projectaswell as the Collaborative lnnovation Centerof Suzhou Nano Science and Technology(NANO-CIC).
文摘Interface between metallic nanoparticles and dielectric silicon substrate can strongly confine electromagnetic field(EM-field)through its localized surface plasmons,together contributing great surface-enhanced Raman scattering(SERS)enhancement.Typically,silicon-based nanohybrids(metallic nanoparticles in situ grown on silicon substrate)have been widely employed as SERS-active substrates in sensing platforms for the detection of chemical and biological analytes.Silicon-based nanohybrids with surface plasmons allow amplifying Raman signals that associate molecular binding events by several orders of magnitude.Together with interfacial architectures for the specific binding of target analyte on the silicon-based nanohy-brid surface,silicon-based nanohybrid-enhanced Raman scattering represents a promising method for increasing reliability and sensitivity.This re-view affords a presentation to the basics of SERS enhancement of silicon-based nanohybrid,illustrates current advances in controllable synthesis of silicon-based nanohybrid substrates,and outlines current implementations to sensors for reliable detection of ultralow amounts of analytes.
