Publication date: 15th December 2025
HgTe colloidal nanocrystals are promising materials for infrared optoelectronic applications due to their broadband IR absorption.[1] However, conventional HgTe nanocrystals exhibit an irregular multipod shape, which hinders the formation of high-density packed films and consequently reduces their electrical performance.[2] In addition, although their relatively low temperature synthesis reduces energy consumption, these nanocrystals lack thermal stability, leading to aggregation and sintering in devices such as infrared imagers.
Here, we report a two-step synthesis approach that combines seeded-growth for the HgTe spherical cores and low temperature CdS shell growth, leading to thermally stable spherical HgTe@CdS core-shell nanocrystals. In the first step, the decoupling of nucleation and growth processes yields monodisperse spherical HgTe nanocrystals, revealing enhanced carrier mobility compared to multipod nanocrystals.[3] Tuning the growth condition enables to cover both the short and mid wave infrared.
More importantly, these spherical nanocrystals are thermally stable enough to support subsequent low temperature CdS thin shell growth.[4] The presence of this CdS shell induces a 400 cm-1 excitonic redshift. In contrast with the HgTe core, no further shift is observed upon annealing, indicating the integrity of the HgTe core. Furthermore, the presence of the shell drastically reduces the imager dark current, enabling higher contrast, while offering long term operation.
Key words: core shell, HgTe, IR, imaging, thermal stability
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.