Question

A solar cell is designed to have a non-reflective coating of a transparent material whose index of refraction is 1.16. What minimum thickness of the film, in nm, for light with a wavelength of 468.43 nm?

Answer 1

Let's name some variables:

d: thickness of film; we're solving for this variable

λ: wavelength of light (in micrometers); λ = 0.46843 μm

n: refractive index; n = 1.16

Given these known and unknown variables, we can solve for d using the following:

λ = 4nd

Now all we have to do is plug in the variables we know:

0.46843 = 4*1.16*d

d = 0.46843/(4*1.16)

d = 0.10095 μm = 100.95 nm