NTHU research team develops PQDs with high stability, self-healing ability

KUALA LUMPUR, June 14 -- NTHU's Professor Hao-Wu Lin of the Department of Materials Science and Engineering; and Professor Chih-Sung, Chuu of the Department of Physics, together with Professor Richard D. Schaller of the Department of Chemistry at Northwestern University have jointly developed perovskite quantum dots (PQDs) with high stability and self-healing ability.

They have applied a simple and cost-effective procedure: spray synthesis, according to a statement.

Their PQDs display unprecedented single-photon brightness. They have also broken the world record for the brightest room-temperature quantum emitter material, a major breakthrough for quantum information processing. Lin says that, in contrast to other quantum emitters, PQDs can realise single-photon emission at room temperature with excellent optical properties, including high quantum yield and high single-photon purity, making them ideal for future quantum computing and quantum communications.

The traditional method of preparing PQDs involves directly mixing two different solutions in a flask. Instead, Lin's research team employed a spray-synthesis method to greatly increase the contact area of the reactants and to grow a uniform protective organic layer on the surface of each PQD.

The resulting PQDs retained their brightness even after 24 hours of continuous excitation under intense light, a dramatic improvement in stability.

A surprising finding is that these spray-synthesised PQDs have a unique self-healing ability. Although the PQDs experienced damage and decay when excited under light of extremely high intensity, they retrieved their original brightness after a break of several minutes.

The team’s research appears in the prestigious international journal ACS Nano, gracing the cover of the most recent issue.

Lin notes that their spray-synthesised perovskite quantum emitter requires only about one per cent of the excitation intensity needed by other quantum emitters, and provides a single-photon brightness exceeding nine million photons per second — the new world record.

-- BERNAMA