Читать книгу Perovskite Materials for Energy and Environmental Applications - Группа авторов - Страница 23

It is necessary to the operation of solar cells to produce electron-hole pairs by absorbing sunlight. Holes and electrons lead to the transition of energy carried by the photons of light into electrical energy.

The number of incident photons S₀ (ν) (per unit area, per unit time and per unit energy) determine the number of generated electron-hole pairs. The photon flux S (x, ν) decreases inside the semiconductor exponentially as:

(1.50)

where ν is the frequency. The absorption process in the semiconductor determines the absorption coefficient α(ν).

At x distance from the surface of the semiconductor the generation rate G(x, ν) of electron-hole pairs can be obtained as:

(1.51)

Where R is the reflectance.

Here an assumption is made that one electron-hole pair is generated by each absorbed photon.