A technological breakthrough has been attained recently, greatly facilitating the commercialization of perovskite solar cells (PSCs).

The feat was achieved by a R&D team of Stanford University, which managed to assemble a batch of minuscule PSCs into a piece with a shelf, which shields the brittle perovskite material without affecting the effect converting light into electricity.

The breakthrough overcomes the two major flaws of PSCs, namely brittle material and small size. The novel design boasts dazzlingly sophisticated array in structure, in emulation of the compound eye of insects.

Since its exposure by media in 2009, the PV conversion rate of PSCs has shot up to 22.1%, almost comparable to mainstream silicon PV cells, up from 3.81% originally, in mere seven years. Market players hail its huge potential, citing its simple manufacturing process, reason for it to be selected as one of the 10 technologies to alter human life by the World Economic Forum (WEF) held in Switzerland last year.

In a paper publicized several months ago, a joint R&D team of the University of Leicester, the University of Nottingham, and the University of Sheffield of the U.K. affirmed that PSCs are most endurable PV cells in environment, capable of recouping investments in less than one year. The conclusion was reached after taking into account various factors, including materials in use, extent of difficulty for manufacturing, production cost, product life, greenhouse-gas emission, pollution, and toxicity.

The enhancement of photoelectric conversion efficiency of PSCs, estimated at 31% at maximum, has slowed down since 2016. For its further development, researchers are also faced with a number of daunting challenges, including the lack of waterproof technology, safety and long-term stability, and enlargement of its size.

Shelf shields brittle perovskite material

Susceptible to the effect of water, heat, oxygen, and ultraviolet ray, PSCs have be sealed and covered with water-absorbing material. In order to enhance the endurance of PSCs in extreme environment, the Stanford University team invents a structure, in emulation of insects' compound eye, to shield the brittle material from the effect of the aforementioned elements without compromising their photoelectric conversion efficiency.

A fly's compound eye consists of 4,000 hexagonal photoreceptors, each capable of sensing only part of the image. In the same manner, scientists fit multiple PSCs onto hexagonal epoxy-resin shelves only 0.05 centimeters wide. Nicholas Rolston, in charge of the project, noted that the epoxy-resin shelf, with high tensile strength, has virtually no effect on the photoelectric conversion efficiency of PSCs, according to tests. Researchers also found that with such design, PSCs continued to generate power at high efficiency, after being exposed to 85 degrees Celsius of temperature and 85% relative humidity for six weeks continuously.

Having applied for temporary patent for the new technology, researchers are stepping up study on how to scatter light into the core of every PSC, in order to boost power-generation efficiency.

(News source: TechNews, photo courtesy of pixabay)