 Guys, I do assume that most of you have seen solar cells already, but just to refresh your memory, I just want to see some of the solar panels on the roof of a building. Solar cell is basically a unit of a solar panel that looks like exactly this. It is a device which converts sunlight into electricity. And in order to understand its working and the role of the solar cell, let's first look at the light which comes from the sun. So here you see light and we call it solar spectrum. You see basically the variation in amount of light with this wavelength or energy. I have divided this spectrum in two parts. The part one, we call it visible light. So this is the light which you basically see. So all around what we see is this part of the spectrum. And the second part of the spectrum is invisible, which we don't see, but that is present around us. So now if I take a very common solar cell, which is silicon solar cell, where silicon is absorbing material, what would happen if the light come on this material? So some part of the light would get absorbed by silicon, but some part of the light would just pass through it. Let's see how it goes. Now you see that this part of the spectrum basically get absorbed by silicon and that produce electricity, whereas this part of the light does not participate at all. So this is one of the limiting factor in this device efficiency. This is what I call the wall. In order to break this wall, I basically deal with this non-absorbing light. How would I do this? I do it by two process. Process where one, where I convert this yellow section of light into red section of light, which is kind of dark, but it's red. I do it, we call this process down shifting, where we basically make lead sulphide particles and make a thin film around 100 nanometer, which is roughly 2000 times thinner than our hair thickness. Once I have this old red section of light, I convert this red section into blue and green section, which is a joving part. And we do it by process called up conversion, where I make Arbium docked titanium dioxide thin film and place some metal nanostructures on top in order to improve the efficiency of this film. Once I have both film ready, I basically place them under the solar cell as the way you can see, and then place a mirror around it so we don't lose any light. So what happens when the light come on this one? So some part of light would get absorbed here, but this yellow light would basically come here and convert it into red light by a process down shifting. Then all the red light would come here in this lower layer and convert it back into this absorbing light. Now let's see how it goes. And now these are the photons which makes this light more brighter. Our aim is to make it 4.5% more efficient than the current solar cell. And that's all. Thank you.