With the solar cell’s technology continuing to develop, scientists are always looking for ways to make solar more efficient, accessible and aesthetically desirable as possible.

One of the most exciting new developments in the solar community consists of constructing thin flexible solar options using organic solar cells.

What are organic solar cells?

The typical crystalline solar cells are normally made of silicon. But these organic solar cells used carbon-based materials instead of silicon as a semiconductor to produce electricity from the sun.

What is perhaps the biggest difference between silicon photovoltaics (PV) and organic photovoltaics (OPV) is in their physical structure.

The organic cells are configured out of compound’s that are usually dissolved in ink and then printed onto thin plastics, meaning that the OPVs can be flexible and included into more places or structures than crystalline photovoltaics. They are also able to be used to make solar windows.   

Organic photovoltaics are new and exciting, they still have a long way to go before their efficiency levels can match those that have already been reaching by silicon based solar cells.

But there is a wide range of the potential applications for organic photovoltaic’s, it may not be long before they become a commonly used solar energy generating technology.  

How do the cells work?

Like monocrystalline and polycrystalline silicon solar cells, these organic solar cells generate electricity through the photovoltaic effect. There are three steps that all these photovoltaic panels take to turn sunlight into electricity.

The first step is the light is absorbed and knocks electrons loose from a semiconducting material. The second is loose electrons flow and create an electrical current. The last step is current is captured and transferred to wires.

The photovoltaic process is the same between silicon solar cells and organic solar cells, but in carbon-based compounds are used instead of silicon as the semiconducting material.

Organic solar cell structure

Organic solar cells are structured similarly to traditional crystalline silicon solar cells. The main difference between the two cell types us the semiconducting layer.

The organic cells use carbon-based compounds (organic molecules) as opposed to crystalline silicon. The carbon-based compounds are printed on a very thin layer onto a plastic backing. The organic solar cells are placed into two categories, Small-molecule organic photovoltaic cells and polymer-based organic photovoltaic cells.

The small-molecule organic photovoltaic cells use molecules with broad absorption in the near and near-infrared portion of the electromagnetic spectrum. This is a more recent development in the organic photovoltaic development.

The Polymer-based OPV cells use long-chained molecular systems for the electron-donating material, along with derivatized fullereness as the electron-accepting system. Like the small-molecule OPV cells, these systems have small exciton diffusion lengths. This circumvented by a high interface surface area withing an active device.

Crystalline solar cells v. Organic cells

There are three main factors on how the organic cells and crystalline solar cells compare: efficiency, materials and pricing. 

Efficiency 

The way that a solar cells efficiency is measured is by what percentage of incoming sunlight that hits the solar cells is converted to electricity. According to the Department of Energy, organic solar cells have exhibited efficiencies topping out at almost 11 percent (though some recent experiments have pushed that muber several percentage points higher in controlled situations).

In today’s market the most efficient solar panels are crystalline solar panels and they have efficiency levels that reach up to 22 percent. The organic photovoltaic’s still have quite a ways to go to match those efficiency levels that are being produced by the silicon-based solar cells.

Materials

The main difference between silicon solar cells and organic solar cells is the semiconducting material used. The material that is being used in silicon solar cells is crystalline silicon and organic cells use a carbon-based organic compound applied in a thin layer to synthetic backing.

Since these organic cells are made using an ink-based process, they are usually create a flexible solar panel that can be installed in quite a few more ways that traditional solar panels. They can be installed on both walls or windows.

Benefits of organic solar cells 

There are a few benefits that come with organic solar cells.

The cost of manufacturing them is not very high. Because the soluble organic molecules, that are used to create these organic solar panels, enable a roll-to-roll processing techniques they allow for low-cost manufacturing.

There are also an abundance of materials for these cells. Because there is an abundance of building-block materials, it may reduce the supply and price constraints.

The also have a flexible structure. Because they are flexible it permits a variety of uses for these panels, uses that are not an option for regular solar panels.

Pricing 

Because organic solar panels aren’t commercially available, there isn’t any pricing comparisons or prices listed.