ACS Applied Materials & Interfaces
ACS Applied Materials & Interfaces
3 years ago

HgSe Self-Doped Nanocrystals as a Platform to Investigate the Effects of Vanishing Confinement

HgSe Self-Doped Nanocrystals as a Platform to Investigate the Effects of Vanishing Confinement
Ricardo P. S. M. Lobo, Hervé Aubin, Clément Livache, Emmanuel Lhuillier, Jean-François Dayen, Mathieu G. Silly, Hervé Cruguel, Bertille Martinez, Emmanuelle Lacaze, Sean Keuleyan, Bernard Doudin, Abdelkarim Ouerghi, Sandrine Ithurria, Nicolas Goubet, Benoit Dubertret, Louis Donald Notemgnou Mouafo
Self-doped colloidal quantum dots (CQDs) attract a strong interest for the design of a new generation of low-cost infrared (IR) optoelectronic devices because of their tunable intraband absorption feature in the mid-IR region. However, very little remains known about their electronic structure which combines confinement and an inverted band structure, complicating the design of optimized devices. We use a combination of IR spectroscopy and photoemission to determine the absolute energy levels of HgSe CQDs with various sizes and surface chemistries. We demonstrate that the filling of the CQD states ranges from 2 electrons per CQD at small sizes (<5 nm) to more than 18 electrons per CQD at large sizes (≈20 nm). HgSe CQDs are also an interesting platform to observe vanishing confinement in colloidal nanoparticles. We present lines of evidence for a semiconductor-to-metal transition at the CQD level, through temperature-dependent absorption and transport measurements. In contrast with bulk systems, the transition is the result of the vanishing confinement rather than the increase of the doping level.

Publisher URL: http://dx.doi.org/10.1021/acsami.7b10665

DOI: 10.1021/acsami.7b10665

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.