Question

The linear absorption coefficient for Si is about 1000 cm^-1 for photons with wavelength 750 nm, while for GaAs it is about 70000 cm^-1. We can shine monochromatic light of this wavelength on a silicon wafer and a GaAs wafer, and measure the relative intensity out the back end of each.

How thick of a Si wafer is needed to absorb 99% of this light?

How thick of a GaAs wafer would be needed to absorb 99% of this light?

Si thickness?????
GaAs thickness??????

Enter your answer in microns, providing two significant figures.

Answer 1

@chmvijay

Answer 2

do u have any formula for this ?

Answer 3

dunno