Organic Solar Cells Explained

Organic solar cells are a relatively new type of solar cell made from carbon materials rather than silicon at the core. Most projects for these types of cell are still in the development phase. However, they are attracting lots of incoming investment as researchers strive to deliver organic cells that can be produced at a relatively low cost while retaining high levels of efficiency.

Organic photovoltaics are made from organometallic compounds that have been dissolved in ink. They are then printed onto thin plastic rolls. The key advantage of these types of solar cells is their flexibility – once developed, they can be incorporated into soft, pliable materials such as clothing or wrapped around structures.

Duncan Clark, Nextgen Nano’s Director of Operations, forms a key part of a team that has been working on breakthrough solar power technology. The patented PolyPower® technology has several innovative qualities, including record efficiencies and unique physical properties. Cutting-edge nanotechnology is blended with environmentally friendly biopolymers to deliver a solar technology that can be used for multiple applications.

Efficiency

One of the main issues holding back organic PV solar power at present is efficiency. This is measured by the percentage of light energy that is converted within the cells into electrical energy. Silicon PVs have an average efficiency rate that is typically somewhere between 15% and 22%, with a record high of 27.3% set by Oxford PV in the UK in 2018. Most organic cells typically have a conversion rate of half the average for silicon cells.

According to the US Department of Energy, OPVs exhibit efficiencies of around 11% at their highest, whereas the most efficient solar panels constructed from crystalline silicon can have efficiencies of 22% or more. However, OPVs have many other advantages that make them a better option in certain cases, and the technology is improving all the time.

Flexibility

The flexibility of OPVs combined with their transparency means they can be fitted in areas where traditional solar cells would be impractical or too costly. OPVs can be used to create solar windows, or incorporated into clothing, aircraft wings or the roofs of electric vehicles.

OPVs also represent low cost in terms of both the environment and investment, making them a cost-efficient alternative in many cases. The true beauty of OPVs is that they can be fitted virtually anywhere, making energy generation possible on an unforeseen scale.

Advantages and Disadvantages

At present, the main disadvantages of OPVs compared to silicon-based solar cells are lower efficiency, strength. and stability. However, these types of cells are more flexible, lightweight and customisable on the molecular level, and are relatively cheap to fabricate.

OPVs can even be generated using printed electronics, driving costs down even further.

Structure

The structure of OPVs is similar to that of their silicon counterparts, in that thin layers of semi-conducting material are sandwiched with fine layers of electrodes, with a current-collecting electrode at the bottom and a clear glass layer at the top.

The main difference is not the structure but the materials – OPVs use carbon-based compounds printed into ultra-thin layers on a plastic backing, rather than silicon.

Organic solar cells are still in the testing and development phase for the most part, so price comparisons cannot yet be made. In terms of efficiency, silicon cells are still way ahead, but in terms of flexibility the OPVs win hands-down.