Semiconductor quantum dots: Technological progress and future challenges

Abstract

In quantum-confined semiconductor nanostructures, electrons exhibit distinctive behavior compared with that in bulk solids. This enables the design of materials with tunable chemical, physical, electrical, and optical properties. Zero-dimensional semiconductor quantum dots (QDs) offer strong light absorption and bright narrowband emission across the visible and infrared wavelengths and have been engineered to exhibit optical gain and lasing. These properties are of interest for imaging, solar energy harvesting, displays, and communications. Here, we offer an overview of advances in the synthesis and understanding of QD nanomaterials, with a focus on colloidal QDs, and discuss their prospects in technologies such as displays and lighting, lasers, sensing, electronics, solar energy conversion, photocatalysis, and quantum information.

Nature of electronic excitations in small non-stoichiometric quantum dots

“…Colloidal II–VI and III–V semiconductor quantum dots (QDs) have found their applications in a broad range of technologies 1–3 such as solar cells, 4–6 light-emitting diodes (LED), 7–9 biological imaging, 10–12 photocatalysis, 13–15 and quantum computing. 16,17 The ability to modify the functionalities of these QDs by precisely tuning their size and combining multiple semiconducting materials in a single nanocrystal underpin these applications.…”

All-solid-state SARS-CoV-2 protein biosensor employing colloidal quantum dots-modified electrode

“…In our all-solid-sate biosensor, the CQD-protein interface is the key parameter that determines the success in realizing the electronic labelling of SARS-CoV-2 antigen for future antibody molecule recognition and signal transduction. In the oleic acid (OA)-capped PbS CQDs, the long-chain (18 carbons) OA ligands serve as metal coordinating groups (Pb–O) as well as solvophilic groups which enable the stabilization of quantum dots in the form of colloids ( Liu et al, 2015 ; Boles et al, 2016 ; Arquer et al, 2021 ). Traditionally, these long-chain ligands are replaced by shorter ligands via ligand exchange process to achieve application-specific electronic and optoelectronic properties for the large-area, solution-based assembly of semiconductor devices ( Liu et al, 2021 ).…”

“…The surface ligands surrounding CQDs are exchangeable, which potentially enables their sufficient adsorption, direct binding, and stable presence on protein surface ( Boles et al, 2016 ). Attractively, CQDs possess unique quantum effect such as quantum confinement, Coulomb blockade effect and quantum tunneling, which may modulate the charge transfer and carrier transport across the CQD-protein interfaces under external electric fields ( Arquer et al, 2021 ; Liu et al, 2021 ). Moreover, CQDs can be solution-processed at room temperature onto a wide variety of substrates, so that their materials properties are well preserved in real devices.…”

Luminescence Enhancement, Encapsulation, and Patterning of Quantum Dots Toward Display Applications

“…provided an overview of the synthesis and understanding of colloidal QDs. [ 24 ] Yang et al. presented the advances in material processing and device technologies for full‐color QLEDs.…”

“…[23] García De Arquer et al provided an overview of the synthesis and understanding of colloidal QDs. [24] Yang et al presented the advances in material processing and device technologies for full-color QLEDs. [25] Especially, Jia et al focused on the blue QLED development.…”