Scientists from the RIKEN Center for Emergent Matter Science and their collaborators have achieved a remarkable feat by developing a superlattice of semiconductor quantum dots that exhibit metallic behavior, opening up new possibilities for these materials. [1]

Figure 1. superlattice.

Figure 1 shows the superlattice. Semiconducting colloidal quantum dots have attracted significant attention due to their unique optical properties stemming from the quantum confinement effect. They find applications in diverse fields such as solar cells, biological imaging, electronic displays, and quantum computing. However, the challenge of enabling efficient electrical conductivity in semiconductor quantum dots has limited their full potential utilization. This limitation arises mainly from the lack of ordered arrangements in their assemblies. [1]

To address this challenge, Satria Zulkarnaen Bisri, the lead researcher on the project, conducted groundbreaking research at RIKEN and is currently affiliated with the Tokyo University of Agriculture and Technology. Bisri and his team, including Yoshihiro Iwasa of RIKEN CEMS, published a study in Nature Communications that contributes significantly to the pursuit of achieving metallic properties in quantum dots. [1]

The key breakthrough was achieved by directly attaching individual quantum dots in the lattice to one another in an epitaxial manner, without the use of ligands, while ensuring precise facet orientation. [1]

To evaluate the conductivity of the newly created material, the researchers increased the carrier density using an electric-double-layer transistor. Remarkably, they observed that at a certain point, the conductivity became one million times greater than what is currently achievable with quantum dot displays. Importantly, despite the enhanced conductivity, the individual quantum dots retained their quantum confinement, ensuring that their functionality was not compromised. [1]

“Semiconductor quantum dots have always shown promise for their optical properties, but their electronic mobility has been a challenge,” says Iwasa. “Our research has demonstrated that precise orientation control of the quantum dots in the assembly can lead to high electronic mobility and metallic behavior. This breakthrough could open up new avenues for using semiconductor quantum dots in emerging technologies.” [1]

According to Bisri, “We plan to carry out further studies with this class of materials, and believe it could lead to vast improvements in the capabilities of quantum dot superlattices. In addition to improving current devices, it could lead to new applications such as true all-QD direct electroluminescence devices, electrically driven lasers, thermoelectric devices, and highly sensitive detectors and sensors, which previously were beyond the scope of quantum dot materials.” [1]

This research represents a significant advancement in quantum dot technology, potentially paving the way for brighter and more energy-efficient quantum dot displays, as envisioned by Bisri. It also opens up possibilities for the development of improved electroluminescence devices, lasers, thermoelectric devices, and sensors, further expanding the range of applications for these remarkable materials. [1]

References:

1. https://scitechdaily.com/metallic-magic-forging-a-dream-material-with-semiconductor-quantum-dots/

Cite this article:

Hana M (2023), Quantum Dots Unleashed: Unveiling the Metallic Potential for a Technological Revolution, AnaTechmaz, pp.120