Abstract
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. CsPbI3 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 CsPbI3 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.
Original language | English |
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Pages (from-to) | 1672-1678 |
Number of pages | 7 |
Journal | Journal of Raman Spectroscopy |
Volume | 50 |
Issue number | 11 |
DOIs | |
State | Published - 1 Nov 2019 |
Keywords
- CsPbI
- DBR microcavity
- cavity resonance peak
- low-frequency Raman
- signal enhancement
All Science Journal Classification (ASJC) codes
- Spectroscopy
- General Materials Science