First single-crystal organometallic perovskite optical fibers

Due to their very high efficiency in transporting electrical charges from light, perovskites are known as the next-generation material for solar modules and LED displays. A team led by Dr. Lei Su at Queen Mary University of London has now invented a brand new application of perovskites as optical fibers. The results will be published in scientific advances.

Optical fibers are tiny wires, as thin as a human hair, in which light travels at super-fast speeds – 100 times faster than electrons in cables. These tiny fibers carry most of our internet data. Currently, most optical fibers are made of glass. The one from Dr. Su’s team made the perovskite optical fiber from just one piece of perovskite crystal. The optical fibers have a core width of only 50 μm (the size of a human hair) and are very flexible – they can be bent to a radius of 3.5 mm

Compared to their polycrystalline counterparts, single-crystal organometallic perovskites are more stable, efficient, longer-lived, and have fewer defects. Scientists have therefore attempted to produce single-crystal perovskite optical fibers that can bring this high efficiency to fiber optics.

dr Su, Reader in Photonics at Queen Mary University of London, said: “Single crystal perovskite fibers could be integrated into current fiber optic networks to replace key components in that system – for example in more efficient laser and energy conversions. Improving the speed and quality of our broadband networks.”

The team of dr. Su was able to grow and precisely control the length and diameter of single-crystal organometallic perovskite fibers in liquid solution (which is very inexpensive to operate) using a new temperature growth method. They gradually changed the heating position, line contact, and temperature during the process to ensure continuous growth in length while preventing random growth in width. With their process, the fiber length can be controlled and the cross-section of the perovskite fiber core can be varied.

Consistent with their predictions, their fibers proved to have good stability over several months and low transmission loss – less than 0.7 dB/cm, sufficient for manufacturing optical devices, due to single-crystal quality. They have great flexibility (can be bent to a radius of only 3.5mm) and larger photocurrent values ​​than that of their polycrystalline counterpart (the polycrystalline MAPbBr₃ similar length milliwire photodetector).

dr Su said: “This technology could also be used in medical imaging as high-resolution detectors. The small diameter of the fiber can be used to capture a much smaller pixel compared to the prior art fiber so we can have the micron scale pixels, giving doctors a much, much higher resolution image to provide a better and more accurate To diagnose. We could also use these fibers in textile absorbing the light clothes or a device with this type of fibers woven into the textile, they could convert the sun’s energy into electrical energy. So we could have solar powered clothing.