Organic Solar Cell

Quantum mechanics paves the way for more stable organic solar cells

Quantum mechanics can be used to create more stable and more easily produced organic solar cells. These are the findings of new research from the University of Gothenburg.

Fig. Organic Solar Cell

Organic solar cells have many advantages compared with traditional silicon-based solar cells. They can be manufactured cheaply at a large scale using printing presses, and they are light, malleable and flexible. The problem is that today's organic solar cells are not as stable and effective as silicon-based solar cells. In a new study, a research group has taken on this problem and found a way that can lead to more cost-effective solar cell technology.

   "There are excellent opportunities for utilising quantum efficiencies to change different chemical and material characteristics. In this study, we present a method that makes it possible to increase diffusion of energy in organic materials. This allows us to create organic solar cells with simpler structure".

   Basically, this is about making sure the energy in the solar cells is effectively transferred to the right place. Organic solar cells contain two materials, and the absorbed energy from the sun needs to be diffused -- to travel -- to the interface between the materials. But diffusion is an ineffective process since the energy travels slowly and risks being lost as heat before it reaches this interface. The solution has been to blend the two materials in solar cells to reduce the distance and so the energy reaches the interface more quickly. Unfortunately, this also leads to the solar cells not being in thermodynamic equilibrium, making design less durable over time than it could be.

  The researchers show that the new method allows the energy to be transferred over a longer distance, which means that the complicated blending of materials in solar cells can be avoided. The key behind the method is quantum effects, where light and material are combined into hybrid light-matter states.