Perovskite solar cells aim to increase the efficiency and lower the cost of solar energy. Perovskite PVs indeed hold promise for high efficiencies, as well as low potential material & reduced processing costs. A big advantage perovskite PVs have over conventional solar technology is that they can react to various different wavelengths of light, which lets them convert more of the sunlight that reaches them into electricity.
Perovskites are a class of materials that share a similar structure, which display a myriad of exciting properties like superconductivity, magnetoresistance and more. These easily synthesized materials are considered the future of solar cells, as their distinctive structure makes them perfect for enabling low-cost, efficient photovoltaics. They are also predicted to play a role in next-gen electric vehicle batteries, sensors, lasers and much more.
The University of Surrey has helped to create a technique that has produced the highest performing inverted perovskite solar cell ever recorded.
Perovskite based cells are widely viewed as the next generation of solar cells, offering similar power conversion efficiency (PCE) performance, but at a much lower cost than the market dominant crystalline silicon based solar cells.
The team created a technique called Solution-Process Secondary growth (SSG) which increased the voltage of inverted perovskite solar cells by 100 millivolts, reaching a high of 1.21 volts without compromising the quality of the solar cell or the electrical current flowing through a device.
They tested the technique on a device which recorded a PCE of 20.9 per cent, the highest certified PCE for inverted perovskite solar cells ever recorded.
A perovskite solar cell is a type of solar cell which includes a perovskite structured compound, most commonly a hybrid organic-inorganic lead or tin halide-based material, as the light-harvesting active layer.
Perovskite materials such as methylammonium lead halides are cheap to produce and simple to manufacture.
Solar cell efficiencies of devices using these materials have increased from 3.8% in 2009 to 22.7% in late 2017 in single-junction architectures, and, in silicon-based tandem cells, up to 26.7% and 25.2% in 4-terminal and 2-terminal configuration respectively.
Perovskite solar cells are therefore the fastest-advancing solar technology to date. With the potential of achieving even higher efficiencies and the very low production costs, perovskite solar cells have become commercially attractive, with start-up companies already promising modules on the market by 2017. In February 2016, a TED talk was dedicated to this technology.
In general, Photovoltaic (PV) technologies can be viewed as divided into two main categories: wafer-based PV (also called 1st generation PVs) and thin-film cell PVs. Traditional crystalline silicon (c-Si) cells (both single crystalline silicon and multi-crystalline silicon) and gallium arsenide (GaAs) cells belong to the wafer-based PVs, with c-Si cells dominating the current PV market (about 90% market share) and GaAs exhibiting the highest efficiency.
Thin-film cells normally absorb light more efficiently than silicon, allowing the use of extremely thin films. Cadmium telluride (CdTe) technology has been successfully commercialized, with more than 20% cell efficiency and 17.5% module efficiency record and such cells currently hold about 5% of the total market.
Other commercial thin-film technologies include hydrogenated amorphous silicon (a-Si:H) and copper indium gallium (di)selenide (CIGS) cells, taking approximately 2% market share each today. Copper zinc tin sulphide technology has been under R&D for years and will probably require some time until actual commercialization.
