The new device precisely controls photon emission, providing more efficient portable screens

Recently, a team of chemists, mathematicians, physicists and nanoengineers at the University of Twente in the Netherlands developed a device to control photon emissions with unprecedented precision. This technology could result in more efficient miniature light sources, sensitive sensors, and stable quantum bits for quantum computing.

The article titled “Strongly inhibited spontaneous emission of PbS quantum dots covalently bonded to 3D silicon photonic band crystals” was published in the journal Journal of Physical Chemistry C.

The part of a smartphone that consumes the most energy is the screen. Reducing unwanted energy emanating from the screen increases the durability of our smartphone. Imagine that your smartphone only needs to be charged once a week. However, to increase efficiency, you need to be able to emit photons in a more controlled way.

MINT tool box

Scientists have developed the ‘MINT-toolbox’: a set of tools from scientific disciplines such as mathematics, computer science, life sciences and technology. This toolkit included advanced chemical tools. The most important were polymer brushes, tiny chemical chains that can hold photon sources in a specific place.

First author Andreas Schulz explains: “Polymer brushes are grafted in solution from the pore surfaces inside a so-called photonic crystal made of silicon. Quite a difficult experiment. So we were very excited when we saw in separate X-ray imaging studies that the photon sources were in the right places on the brushes.”

By adding nanophotonic tools, the team showed that excited light sources were slowed down by almost 50 times. In this situation, the light source remains excited 50 times longer than usual. The spectrum coincides very well with the theoretical spectrum calculated using advanced mathematical tools. Second author Marek Kozoň says: “The theory predicts zero light because it refers to a fictitious, infinitely extended crystal. In our real, finite crystal, the emitted light is non-zero, but so small that it constitutes a new world record.”

The new results herald a new era of efficient miniature lasers and light sources for qubits in photonic circuits with highly reduced interference (caused by elusive vacuum fluctuations). Willem Vos says: “Our multifunctional toolkit offers opportunities for completely new applications that take advantage of highly stabilized excited states. They are crucial for photochemistry and could become sensitive chemical nanosensors.”