The shimadzu uv - 3101 spectrophotometer was employed to get the uv - visible transmission and reflection spectra . both of the absorption coefficient ( a ) and optical band gap ( eg ) were calculated from the transmission and reflection spectra of the films . it was observed that eg decreased with an increase in the deposition pressure 采用紫外-可见光分光光度计测定了纳米- sic薄膜透射光谱和反射光谱，并通过样品的透射光谱和反射光谱计算了纳米- sic薄膜吸收吸收系数和光学带隙eto实验结果表明，增大工作气压导致纳米- sic薄膜的光学带隙的减小。
