Graded band gap a-Si, S : H. thin Films for high efficiency solar cells

Abstract EN

Theoretical work has shown that the maximum expected photo voltage is equal to the band gap variation along the excited region.

Thus, graded band gap material has the potential to collect the maximum solar radiation and creates a high density of electron-hole pairs.

We have shown in a previous work that addition of sulfur atoms to the silicon matrix increases the band gap ofa-Si.H thin films.

We used this fact to prepare a variable band gap material by either increasing gradually the sulfur content in the plasma discharge or decreasing continuously the plasma power delivered to the gaseous mixture.

The potential use of this material for solar cell application is investigated.