Engineering LHPs for Next-Gen LEDs
A new technique developed at NC State allows researchers to engineer layered hybrid perovskites (LHPs) down to the atomic level, opening up the door to creating materials tailored for use in next-generation printed LEDs and lasers.
LHPs can efficiently convert electrical charge to light and light into electricity. They consist of thin sheets of perovskite semiconductor material that are separated by thin organic “spacer” layers. But researchers could not figure out how to engineer these materials to control their performance.
The NC State team discovered that nanoplatelets, which are individual sheets of the perovskite material, form spontaneously at the surface of solutions and can play a key role in the properties of the LHP films — if they can be controlled.
Within LHPs are quantum wells, which are sheets of semiconductor material sandwiched between spacer layers. Nanoplatelets serve as LEGO pieces of different thickness, where the thickness determines the quantum confinement and the energy. If the series of nanoplatelets have a thickness of two, three and four atoms in ascending order, the LHP can form efficient energy cascades.
“What’s exciting is that we found we can essentially control the growth of several nanoplatelets at once, essentially tuning the size and location of quantum wells in LHP films in a reproducible manner,” said Aram Amassian, professor in the Department of Materials Science and Engineering. “And because we can control their arrangement, energy can cascade more efficiently between the quantum wells and undergo recombination — which means the material is highly efficient at converting this energy into light in laser and LED applications.”
This post was originally published in College of Engineering News.
