New Perovskite material from NTU turns solar cells into display panels

If new research from Singapore’s Nanyang Technological University (NTU) holds true, a new solar cell material could one day turn your mobile or tablet display into a solar cell, letting you recharge simply by putting it out in the sun!

NTU researchers have developed a next-generation solar cell material that is not only able to convert light into electricity, but can also emit light. The solar cell (pictured above) was developed using a class of materials called Perovskites, which could hold the key to creating high-efficiency and inexpensive solar cells.

NTU Assistant Professor Sum Tze Chien explains “What we have discovered is that because it is a high quality material, and very durable under light exposure, it can capture light particles and convert them to electricity, or vice versa”. Further, the cell can be customised to emit different colours. Sum adds, “By tuning the composition of the material, we can make it emit a wide range of colours.”

As sometimes happens in science, the light emitting nature was discovered almost by chance when the NTU team exposed their hybrid Perovskite material to a laser. The researchers were surprised when the material glowed brightly when the laser beam was shone on it, instead of simply reflecting the laser off the cell surface as happens with most materials (including Silicon). This accidental finding was quite significant since most solar cell materials are good at absorbing light but are generally not expected to generate light.

As NTU Assistant Professor Nripan Mathews adds, “Since we are already working on the scaling up of these materials for large-scale solar cells, it is pretty straightforward to modify the procedures to fabricate light emitting devices (LEDs)”. The high luminescence makes the Perovskite material very suitable for lasers, light detectors and even flat-screen displays – in addition to solar cells. In fact, it may be possible to make a flat-screen display that doubles as a solar cell (for example, in the screen of a smartphone).

From a photovoltaics/solar energy perspective, Perovskites have other interesting applications since Perovskite-based solar cells “can be made semi-translucent”. The material is thus useful for Building Integrated PV (BIPV) since “it can be used as tinted glass to replace current windows, yet it is able to generate electricity from sunlight”. As NTU, Assistant Professor Nripan Mathews surmises, “Such a versatile yet low-cost material would be a boon for green buildings.”

While such versatile materials are not unknown to scientists, Perovskites have created quite a buzz lately in the solar research community since it has serious potential to give silicon a run for its money. Solar cell efficiencies made from Perovskites jumped from 3.1% to well over 16% in only 4 years, giving the technology the fastest growing learning curve of all PV cell technologies.

But ultimately, it is the cost and ease of making Perovskite solar cells that makes them so lucrative. For example, Perovskite solar cells can be made up to five times cheaper than current Silicon-based solar cells because almost all of the manufacturing steps are based on chemical processing which can be done at room temperature. In comparison, silicon solar cells require extensive processing at high temperatures, which adds significant costs to the manufacturing cost.

And now with fascinating light-emitting properties to boot, it will be interesting to see how Perovskite materials break into the PV and electronics industries. Watch this space.

Top Image Credit: Nanyang Technological University

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