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Microcavity enhancement of low‐frequency Raman scattering from a CsPbI 3 thin film
Author(s) -
Uliel Tal Ben,
Gouda Laxman,
Aviv Hagit,
Itzhak Anat,
Tischler Yaakov R.
Publication year - 2019
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.5715
Subject(s) - materials science , raman spectroscopy , raman scattering , thin film , signal (programming language) , optoelectronics , optics , optical microcavity , q factor , resonance (particle physics) , wavelength , characterization (materials science) , planar , scattering , resonator , nanotechnology , laser , physics , computer graphics (images) , particle physics , computer science , programming language
Low‐frequency Raman (LFR) spectroscopy is a powerful, nondestructive method used for chemical and structural characterization of materials. Typically, the signal intensity of LFR is relatively low, resulting significantly longer signal acquisition duration. Here, we show a photonic structure based on a planar optical microcavity consists of two distributed Bragg reflectors that is capable of enhancing the LFR signal of the material placed in between the mirrors. CsPbI 3 forms smooth and uniform thin films and has distinct LFR signatures; thus, we chose to use it for investigating the microcavity enhancement capabilities. By compromising the quality factor of the cavity, we achieved a broader transmission peak and essentially earned enhancement from the double‐resonance effect. Measurements on a CsPbI 3 thin film inside a cavity compared with a bare film spin coated on glass demonstrated two orders of magnitude enhancement. In addition, we fabricated the microcavity with a gradient in the resonance wavelength, in order to study the tuning effect on spectral features and on the enhancement factor. Our results show that microcavity is a promising device for enhancing LFR scattering signal and for sensitive characterization of nanomaterials.