Journal of Physical Chemistry Letters
Journal of Physical Chemistry Letters
5 years ago

Ultrafast Carrier Trapping in Thick-Shell Colloidal Quantum Dots

Ultrafast Carrier Trapping in Thick-Shell Colloidal Quantum Dots
Pawel Hawrylak, Edward H. Sargent, Ankit Jain, Marek Korkusinski, Oleksandr Voznyy
It has previously been found that Auger processes can lead to femtosecond carrier trapping in quantum dots, limiting their performance in optoelectronic applications that rely on radiative recombination. Using atomistic simulations, we investigate whether a shell can protect carriers from Auger-assisted trapping. For these studies we investigate CdSe/CdS core–shell quantum dots having total diameters reaching up to 10 nm. We find trapping lifetimes as fast as 1 ps for 2 nm shells, and we report that shells as thick as 6 nm are required to suppress trapping fully. The most efficient recombination mechanism is found to proceed through shallow empty traps, suggesting it can be suppressed by filling the traps through doping or external electrochemical potential. Our findings suggest that to achieve efficient light emission, surface traps have to be completely eliminated, even in thick-shell quantum dots.

Publisher URL: http://dx.doi.org/10.1021/acs.jpclett.7b01503

DOI: 10.1021/acs.jpclett.7b01503

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.