Two water soluble organic dye compounds, methalene-blue [C16H18ClN3(S)3, H2O] and crystal-violet [C25H30CIN3] have been prepared in extremely thin film form on polished silicon wafers. The optical properties, namely the index of refraction and extinction coefficient, have been measured as a function of wavelength from 300nm to 700nm using variable angle spectroscopic ellipsometry. Methalene-blue exhibits transparency from 300 to 460nm with gradually increasing absorption towards the red, whereas crystal-violet exhibits a more resonant-like absorption near 540nm. The index of refraction shows strong wavelength dependence, in agreement with Kramers-Kronig causality requirements. A third organic, tetrasulphonated phthalocyanine containing copper [CuTSPc] was studied, with results agreeing semiquantitatively with published optical constants for this material.
|Number of pages
|Applied physics communications
|Published - Jun 1992
ASJC Scopus subject areas
- General Engineering