Publication date: 15th May 2025
The short-wave infrared (SWIR) region of light (1000-2000 nm) enables remarkable penetrative imaging and sensing applications. However, the widespread use of SWIR technology is limited by the high cost of semiconductor processing and limited quantum yields of small molecules. Semiconductor nanocrystals have emerged as modern alternatives to traditional SWIR materials due to their cost-effective syntheses, optical tunability and solution processability. Of the SWIR emissive nanocrystals, HgTe quantum dots show the greatest degree of spectral tunability (optical features from 1-60 microns), robust stability to air and high photoluminescent quantum yields (30-75%). Here we demonstrate a low temperature nucleation of ultrasmall HgTe quantum dots (1.6 – 3 nm in diameter) and near unity quantum yields (95%) in the near-wave infrared (800-1000 nm). The ultrasmall HgTe quantum dots retain high quantum yields and photostability in thin films allowing for the first single-particle photoluminescence microscopy study on HgTe quantum dots. However, the cold injection synthesis can only isolate HgTe quantum dots with photoluminescence ranging from 900-1180 nm, leaving most of the SWIR region unsampled. To grow larger quantum dots, our previous synthesis was optimized to now include a slow injection of tellurium precursor (TOPTe) into the reaction flask over the course of hours. The slow injection allows the growth of significantly larger quantum dots (> 4 nm) while retaining high quantum yields (70%) out to 1450 nm. The secondary slow injection step seems to prevent the onset of interparticle ripening leading to a more standard growth mechanism resulting in improved monodispersity and photoluminescence linewidth. The slow-injection HgTe quantum dots display spherical shape, retain bright photoluminescence in the solid state, and can readily undergo complete ligand exchanges. We demonstrate their application through a ligand exchange procedure with a thiol terminated polyethylene glycol polymer, rendering them water-soluble and biologically non-toxic. The water-soluble HgTe quantum dots are currently being used as contrast agents for in-vivo SWIR imaging studies of mice.
nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.
Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.
International Conference on Hybrid and Organic Photovoltaics
International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.
Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics
The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.
The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.