Accession Number : ADA593744


Title :   Direct and Quantitative Photothermal Absorption Spectroscopy of Individual Particulates


Descriptive Note : Journal article


Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MECHANICAL ENGINEERING


Personal Author(s) : Tong, Jonathan K ; Hsu, Wei-Chun ; Han, Sang E ; Burg, Brian R ; Zheng, Ruiting ; Shen, Sheng ; Chen, Gang


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a593744.pdf


Report Date : Jan 2013


Pagination or Media Count : 6


Abstract : Photonic structures can exhibit significant absorption enhancement when an object s length scale is comparable to or smaller than the wavelength of light. This property has enabled photonic structures to be an integral component in many applications such as solar cells, light emitting diodes, and photothermal therapy. To characterize this enhancement at the single particulate level, conventional methods have consisted of indirect or qualitative approaches which are often limited to certain sample types. To overcome these limitations, we used a bilayer cantilever to directly and quantitatively measure the spectral absorption efficiency of a single silicon microwire in the visible wavelength range. We demonstrate an absorption enhancement on a per unit volume basis compared to a thin film, which shows good agreement with Mie theory calculations. This approach offers a quantitative approach for broadband absorption measurements on a wide range of photonic structures of different geometric and material compositions.


Descriptors :   *ABSORPTION SPECTRA , *PHOTOTHERMAL PROPERTIES , *QUANTITATIVE ANALYSIS , BROADBAND , CANTILEVER BEAMS , COMPUTATIONS , GEOMETRY , MEASUREMENT , MIE SCATTERING , PARTICULATES , PHOTONS , SILICON , SOLAR CELLS , SPECTROSCOPY , STRUCTURES , THIN FILMS


Subject Categories : Radiation and Nuclear Chemistry
      Atomic and Molecular Physics and Spectroscopy


Distribution Statement : APPROVED FOR PUBLIC RELEASE