Abstract
In the last two decades, colloidal semiconductor nanocrystals have emerged as a phenomenal research topic due to their size-dependent optoelectronic properties and to their outstanding versatility in many technological applications. In this review, we provide an historical account of the most relevant computational works that have been carried out to understand atomistically the electronic structure of these materials, including the main requirements needed for the preparation of nanocrystal models that align well with the experiments. We further discuss how the advancement of these computational tools has affected the analysis of these nanomaterials over the years. We focus our review on the three main families of colloidal semiconductor nanocrystals: group II-VI and IV-VI metal chalcogenides, group III-V metal pnictogenides and metal halides, in particular lead-based halide perovskites. We discuss the most recent research frontiers and outline the future outlooks expected in this field from a computational perspective.
Highlights
Research on colloidal semiconductor nanocrystals (NCs) has gained growing importance over the last few decades as a consequence of their remarkable characteristics
We focus our review on the three main families of colloidal semiconductor nanocrystals: group II-VI and IV-VI metal chalcogenides, group III-V metal pnictogenides and metal halides, in particular lead-based halide perovskites
The many technological applications of NCs span optoelectronics[1] – for instance, they are regarded as key components in the fabrication of light-emitting diodes (LEDs),[2,3,4] optical sensing,[5,6] instrumentation in the medical/biotechnological field[7,8], up to photovoltaics and photocatalysis.[12–22] These nanocrystallites are characterized by several promising features: size-tunable bandgaps, sharp emission spectra, high extinction coefficients, large carrier mobilities[23,24] and in some cases the possibility to increase the number of excitons emitted through carrier multiplication.[25]
Summary
Research on colloidal semiconductor nanocrystals (NCs) has gained growing importance over the last few decades as a consequence of their remarkable characteristics. For instance, made use of tight-binding models[32] to explain the electronic structure and recombination mechanisms of NCs, along with several other features of these crystallites.[32,33,34] Ekimov, on the other hand, joined forces with his colleague Alexander Efros to develop a model to link the size dependence of the NCs with their optoelectronic features.[35] Some years later, in 2000, Efros published a review[36] detailing a theoretical description of the excitonic and band gap structures in spherical semiconductor nanocrystals. Semiconductors, regarded as a litmus test for the characterization of their corresponding finite nanocrystallites These approaches gave valuable insights, they suffered an inherent lack of surface and size-dependence; key features in the description of colloidal semiconductor NCs. As a matter of fact, the first attempts to include such effects involved DFT calculations on small clusters of semiconductors (dimensions of the order of a few unit cells). Breakthroughs in the modelling of NCs and the concomitant increase in computational power have paved the way to the atomistic description of NCs counting up to thousands of atoms, with sizes and shapes aligned with the experiments
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
