用椭圆偏振光谱法研究取代基对酞菁薄膜光学常数的影响

利用M-2000UI型宽光谱可变入射角椭偏仪研究十六氟铜酞菁(F16CuPc)和铜酞菁(CuPc)薄膜的光学性质. 在248～1 650 nm使用逐点拟合的方法对测得椭偏光谱进行分析, 获得两种薄膜的折射率、消光系数、复介电常数和吸收系数. 讨论了外环氟取代基对酞菁光学性质的影响, 结果表明, 共轭酞菁大环上的外围取代基对薄膜的响应波长和非正常色散影响较大. 分析了两种酞菁的电子结构及吸收谱成因, 并由吸收边外推得到两种材料的光学禁带宽度(Eg).

Influence of Substitutes on Optical Properties of Phthalocyanine Thin Films Studied with Ellipsometry

Optical properties of copper phthalocyanine ( CuPc ) and perfluorinated copper phthalocyanine (F_(16)CuPc) thin films were studied by means of spectroscopic ellipsometry on a variable angle spectrometric ellipsometer. Thin films of these phthalocyanines were prepared on single crystal silicon substrates. Spectroscopic ellipsometry measurements were performed at different angles of incidence (55° ,60° ,65° and 70°) in a wavelength range of 248 ～ 1 650 nm (0.75 ～5 eV). The spectral dependences of optical constants, dielectric functions and absorption coefficients of these films were obtained by the simultaneous point-by-point fitting of the experimental data. It has been found that the substituting groups on the conjugated phthalocyanine macrocycles strongly influence resonance wavelength and abnormal dispersion of the thin films. The optical band gap ( E_g) of each material was also derived from the extrapolation of the edge of absorption.