New silicon solar panels combine efficiency and flexibility by adapting to any surface

Scientists develop silicon solar panels that combine efficiency and flexibility. Equipment promises to change the solar energy market.

As organic solar cells, developed with plastic, are great promises for the solar energy market, they can be manufactured on flexible and transparent bases, making it possible to place them in glass windows or on irregular surfaces. However, it is possible that it will not be necessary to wait for technological progress for them to become durable enough to reach the market and take the place of the conventional silicon solar panels, which are rigid and costly to install.

Efficiency of new solar panels are greater than 24%

Researchers at the Institute of Microsystems and Information Technology in Shanghai, China, managed to produce a solar panel traditional silicon, with the same solar cells currently on the market, that is bendable enough to fuse to uneven surfaces.

The solar panel, 60 micrometers thick, is as flexible as a sheet of paper and maintains the same efficiency even when rolled up. The only cost for the modification was a slight drop in the efficiency of converting solar energy into electrical energy compared to the original solar panel, but that remained above 24%.

Wenzhu Liu and his friends started with a standard wafer of silicon cells 160 micrometers thick and have since used alkalis concentrates to corrode pads down to a minimum thickness of 60 micrometers without loss of functionality. However, a series of challenges arose. After thickness reduction, the silicon solar panel it becomes so polished that it reflects about 30% of the incident light as it is bent, which greatly reduces its efficiency.

Solution found by scientists for new solar energy panels

In this way, the team of researchers did the opposite job, using another more diluted compound to generate surface grooves, obtaining microscale patterns that resemble pyramids.

The reflectivity disappeared, so the panel lost its flexibility, as it cracked very easily. According to Liu, for several years the scientists it has difficulty balancing light reflection and flexibility, which explains why the vast majority of efficiencies obtained from flexible crystalline silicon solar cells have been relatively low.

The scientist then focused on studying the appearance of cracks using high-speed cameras and discovered that cracks always start at the edges of pyramids. With that, he then used a mixture of acids to remove the texture from the edges and the wafers immediately regained their flexibility.

More detailed analyzes showed that the smooth region dissipates the mechanical stress of the bend, making it possible for the textured region to form a network of microcracks, rather than suffering a drastic fracture at a single point. The team plans to start laying its flexible panels to cover aerospace structures such as airplane wings, drones and research balloons. 

Brazil also develops organic solar panel

O organic solar panel, which has organic solar cells, is seen as the third generation of solar cells, that is, it is at the top from a technological point of view.

The new solar panel is developed in a totally different way compared to common panels, being developed with a plastic film, where carbon inks are printed, making the plastic film have layers, getting electrons on the top, with a charge positive at the top and negative at the bottom. The equipment provides several benefits, as it is a plastic film that uses extremely flexible, low-cost and transparent carbon-based inks.