Comments on Anti-Reflection Coatings


I want to plot reflectance of silicon vs wavelength. I have values for real and imaginary part of the refractive index. How can I get value of complex index of refraction from it ?
I referred to the excel file provided by you guys. But I am using different equations for plotting reflectance where I need to input value of complex index of refraction. Actually I want to extend this to GaAs Solar cell which has texture on its surface.

Please tell me how to calculate the right value of the wavelenght in order to calculate the right thickness of the ARC. Thanks in advance.

How is the formula for the reflectivity derived? Is multiple reflection considered?