00:03
So in this question, you look at solar sales and the efficiency of solar sales, which is given in this question, which i copied down here.
00:12
This is the graph that shows how the efficiency of a solar sale depends on the band gap of the materials.
00:20
So you know that actually all of the solar cells use semiconductors, which has a bandagap that separates the conduction band.
00:30
Right, which is normally writing as cn or conduction band.
00:36
And you also have the valence band.
00:43
And the gap, this is called the band gap, which is known as eeg, right? so a solar cell works, you know, by absorbing, you know, at loom temperature without light, the electrons basically populate this valence band.
01:02
There's very few electrons in conduct.
01:05
So basically we saw that there's a lot of holes here and the electrons here, right? and what happens when you shine a beam of light on the semiconductor is that the electrons gets excited and then come to combine with the horse, right? so you get electrons, some electrons on this conduction band, and then they can generate current, right? so obviously, the energy of the photon that can generate such electron whole, such carriers, okay, we call them carriers, you get electrons on the conduction band and you get a horse come down to the balance band and those electrons in the conduction man and a horse in the valence band are called carers...