Graphene Solar Cells Help Address Global Energy Needs

The reliance on renewable energy has been growing by leaps and bounds and with this, so is the need for efficient devices for the synthesis of energy from renewable sources. Graphene-based solar cells are fast emerging as a hit, considering both graphene (an allotrope of carbon) and solar energy are available in abundance. Graphene exhibits phenomenal tune ability and adaptability andlatest advancements in these solar cells have resulted in a 20 per cent reduction in reflectance of solar rays. This provides a potential efficiency boost of up to 20%.

Based on doping mixture used and the number of graphene layers in the device, the nature of the device for graphene-based solar cells can be varied. Moreover, such kind of cells can be developed with a predetermined thickness and a complete coverage.

Graphene - the “Wonder Material”

Despite being made up of a single layer of carbon, graphene is highly strong and mostly transparent. The material is gaining popularity for its superior conductivity and flexibility. Owing to these properties, it is often referred to as “wonder material”. According to a study by Grand View Research, Inc., soaring uptake of graphene will help the global market to expand at a CAGR of 36.7% between 2016 and 2025.

Graphene is emerging as a replacement for indium tin oxide (ITO) in transparent electrodes for photovoltaics. ITO is conductive in nature and is used with a non-conductive glass layer in most organic solar panels. However, ITO is brittle and is also rare, which makes it expensive to use. Therefore, several researchers are focusing on graphene. It is being utilized to improve overall performance of photovoltaic devices, primarily organic photovoltaics (OPVs), as well as in active layers, electrodes, electron acceptors, and interfacial layers.

More Power to Graphene-based Solar Cells

Graphene is an excellent conductor, but is not as good when it comes to collecting electrical current produced within solar cells. Thus, researchers are focusing on research and development activities to modify collector properties of this carbon derivative. Graphene oxide (GO), for instance, is less conductive but a better charge collector and more transparent, which can boost the efficiency of solar panels. A recent study by a team from the University of Florence showed that GO can substantially enhance the efficiency of perovskite solar cells. Researchers say that incorporating graphene and graphene oxide doped with Li atoms (GO-Li) into a perovskite-based cell may augment its conversion efficiency.

Imparting Flexibility to Solar Cells through Graphene

In the coming years, solar cells are expected to emerge ubiquitous. In order to tap into the immense potential of graphene, researchers are extensively using the material for the development of novel solar panels. For instance, in July 2017, a team of researchers at MIT developed transparent and flexible solar cells using graphene, whichcan be mounted on surfaces ranging from glass to plastic and paper. Until now, transparent solar panels were manufactured using expensive and brittle electrodes, which were prone to cracking upon flexing. The cells developed by MIT researchers are low-cost, trulyflexible, and transparent thanks to graphene and have the ability to turn virtually any surface into an electric power source. Currently, researchers are focusing on improving the efficiency of these cells.

Of late, developing flexible solar cells has been one of the primary areas of attention for researchers worldwide. For instance, in April 2017, scientists from RMIT University, Australia, developed a novel graphene-based electrode that can trigger the capacity of existing solar integrable storage technologies by 3,000 percent. This development opens avenues for the development of flexible, thin film solar cells, bringing us a step closer to self-charging electronic devices, automobiles, and buildings.