In this video, I want to give you

a really brief overview of some emerging solar cell technologies.

As from last time we have the NREL graph of all the research cell efficiencies,

and you can see that the emerging PV technologies are basically this area.

We also include in this discussion multijunction solar cells.

So first off, we start off with organic solar cells.

Organic solar cells is a broader category that

includes polymer solar cells that we discussed in the last module.

The other main type of solar cell is small molecules

solar cells whether the small molecules are evaporated onto the substrate.

Record efficiencies for organic solar cells are on the order of 12%,

and as you know,

one of the main problems with them is stability,

so the lifetime of this kind of solar cell is not nearly as high as,

for example, silicon solar cells.

The good news is that they can be flexible,

they can be produced really really fast.

They can be made with a really low energy payback time

and they can have really low environmental impact.

Perovskite solar cells are a new type of solar cell within research.

It's now around 22% efficient and is actually really impressive.

So back in 2009 the record efficiency was around 3.8.

So it's the fastest developing solar cell technology that we've ever seen.

The good news about perovskite solar cells is that they can be made like

polymer solar cells so good, solution processable materials.

So we can have really fast manufacturing.

A main drawback is that they contain lead,

so they contain a heavy metal making them toxic,

and making the work with them more problematic than for other types of solar cells.

Another really big problem at the moment for perovskite solar cells is the stability.

So the lifetime of these types of solar cells

is really low at the moment, and we can even see,

if we look at the NREL graph we have that 22.1% efficiency that's recorded for it,

is not stabilize solar cell.

So, for Perovskite solar cells,

stability is still a main issue that needs to be worked on.

But there is a lot of research going into

this area and Perovskite solar cells will improve.

Another type of technology is dye-sensitized solar cells.

So you may know dye-sensitized solar cells as jam or color-based solar cells.

You can find videos on YouTube where you can find instructions

on making your own solar cell based on this technology.

They're quite simple to manufacture and they can use low cost materials.

The record efficiencies of dye-sensitized solar cells are on the area of 15%.

A major drawback is that dye-sensitized solar cells use a liquid electrolyte.

And this gives a lot of problems with stability and the places they can be used.

The last type of solar cells that I will mention here is multijunction solar cells.

You remember these back from the first week when we talked about space applications.

So the main drawback of this type of solar cell

is that they are really expensive to produce.

However, they can have really, really high efficiencies.

So since we are using more than one junction,

we can use a lot more of the light,

and regular efficiencies are on the order of 46%.

The problem, of course, is that they are expensive and complicated to manufacture.

If we were to see them in terrestrial applications,

it'll only be in concentrators systems.

So now we have an overview of all of

the emerging PV technologies including multijunction solar cells.

It's outside the scope of this course to go into much more details.

But I encourage you to read up on the topic.

Emerging solar cell technologies

Introduction to solar cells

Meet the Instructors