How can I get the total absorption/absorbance of the whole surface of a quantum dot in a QD solar cell by varying the angles theta and phi?

Hi there,

I was doing a research on Quantum Dot in Solar Cell and I thought your software could be very useful for my work. I was intending to vary the size and shape of quantum dots and see the output absorbance of the solar cell. I know I can vary the angle theta, but how can I put a range on both of the angles so that I can get the total absorbance of the whole surface? Or if I have to integrate over the whole surface, what equation should i be using?