How Graphene is taking Solar Cells to the next level

hi welcome to this video in which we will show you how graphene is positively impacting solar PV systems on this channel synergy files we aim to inspire budding engineers and technicians for a better more sustainable world subscribe to the channel for more such videos help a channel grow by hitting the like button graphene as we all know has been cited as the miracle material it is one form or more scientifically one alert rope of pure carbon its remarkable properties have opened up several avenues of research graphene is a single atom layer thick sheet of carbon so essentially it is a 2d material it is very flexible and efficient thermal and electrical conductor it also has very high strength and is optically transparent this makes it extremely interesting material for scientists as there are many materials that are conductive but they are not transparent and for this reason graphene lends itself for application in photovoltaics at present several different variation of graphene based solar cells are being researched even for the best of students it is difficult to read the scientific journals and get the measure of various strands of research because of the terminology and so we have broken down the jargon in this video and we'll present the ongoing work in an easy-to-understand language there are three main areas where graphene is helping solar panels push the boundaries of performance the first is there used as electrode or charge carriers the second is their use as photovoltaic material and third as their use as a charge holder we'll discuss each of them individually first we look at graph is used as an electrode or a charge carrier the relatively higher electric conductivity of graphene is widely known for a semi metal it has an impressively low resistance value of 3.1 microns per centimeter square this sounds even more astounding when you consider that graphene is a two-dimensional material if you look at an ordinary we sell then we find metal strips covering it these strips or mesh wires are there to collect the free electrons knocked out by the sunrays there are two disadvantages of having these strips firstly they do not cover all the areas for collecting the electrons and there is a reason for that which is in fact a second problem the rays of Sun are blocked by these metal strips on areas covered by them this mesh of conducting strip sits right at the top and can block up to five percent of the sun rays reaching the pv cell which reduces the overall output this is exactly where graphene fits in it is transparent and it can collect electrons knocked out by the Sun base thus improving the overall efficiency of the panel also the layer of graphene is flexible and does this ideal for organic solar cells whose unique selling point is their flexibility graphene is also an indispensable material for panels that require flexibility as well as transparency at present indium tin oxide I tio is widely used although this material is conductive and transparent but it is stiff and brittle it cracks up when the cell is flexed and therefore graphene is an ideal replacement as a flexible electrode it has to be further noted that I tio is expensive as only five grams of it costs about $200 it can also cause damage to the organic layer and the oxide layer which is very sensitive to wear on the other hand the bonding with graphene is more natural and smooth in short graphene can not only be used to improve ordinary silicon solar cells as an electrode but also it can be used for transparent and flexible solar cells next up we look at graphene's use as a PV material now we understand that almost all solar cells are based on the combination of P and n-type semiconductor material there is a new breed of PV cells emerging that are based on Schottky Junction diodes this is an attempt to increase the efficiency of solar cells by using slightly different process than PN type cells and adding an impurity energy level in the bandgap through the use of new materials and one of these new materials is doped graphene it has been reported that graphene silicon Schottky cells have reached efficiencies of ten point six nine percent while graphene perovskite cells have surpassed efficiencies of 20.3% in lab tests finally let's now examine another use of graphene in solar cells as a charge collector the third main area of research for graphene and PV is its use as a charge holding parallel plate just like in a capacitor scientists from Ocean University of China have been working on harnessing the power of rain through solar panels as we all understand that rainwater is not pure and it has positively charged ions of sodium calcium and ammonium a layer of graphene is placed on the top of the solar cell not as a current collector but as an iron holder and a separator the solar panel is sandwiched between the layer of graphene at the top and I T o and plastic at the bottom what happens is that the positively charged ions bind to the ultra thin layer of graphene forming a double layer technically referred to as a pseudo capacitor with the electrons already present the potential energy difference between the two layers is strong enough to generate an electric current so far the energy conversion efficiency has reached six point three percent but it is the ability to generate electricity come rain or shine that is the exciting prospect of this technology in other words we can now create an all-weather solar panel courtesy of graphene so that's it we have tried to cover in this video how graphene is taking solar cells to the next level obviously the cost of extraction of graphene is a stumbling block but not one that can be overcome with a bit of commercial interest and with this the video is concluded please hit the like button if you learn from the videos subscribe to the channel for more tech related videos thank you for your attention

Channel: Synergy Files

Views: 379,541

Rating: 4.871532 out of 5

Keywords: Graphene in Solar Cell, Graphene Perovskite Solar Cell, Graphene in solar panel, Schottky junction solar cell, Energy from rain water

Id: BKomGuejwRA

Length: 6min 55sec (415 seconds)

Published: Fri Aug 31 2018