Optical and electrical properties of an organic superconductor di[bis(ethylenedithio)tetrathiafulvalenium dithiocuanocuprateI, (BEDT-TTF2[Cu(SCN)2]

A single crystal of (BEDT-TTF${)}_2$[Cu(SCN${)}_2$] was prepared and its reflectance spectrum and electrical resistivity were investigated. The optical anisotropy was found to be very small. The spectrum in the infrared region was concluded to be dominated by the interband transitions for the directions parallel to both b and c. From the analysis of the spectra measured at 25 K, the effective masses were estimated to be $m_b^{\mathrm{*}}$=5.5$m_e$ and $m_c^{\mathrm{*}}$=4.1$m_e$, respectively. The material was proved to be metallic over the temperature range from 300 down to 10 K, and become superconductive at 11 K.