Abstract
Owing to its simplicity and versatility, the successive ionic layer adsorption and reaction (SILAR) method is increasingly being employed to develop low-cost hetero-nanostructured sensitized oxide systems for solar energy conversion, such as solar cells and solar fuels schemes. Understanding the nature of the SILAR quantum dot (QD) nucleation and growth on an insulating oxide is then critical as it will determine the QD density and spatial distribution, as well as the optoelectronic properties of the QD/oxide interfaces (e.g. QD bandgap onset). Here, we demonstrate epitaxial nucleation of lead sulfide (PbS) QDs onto a planar rutile titanium dioxide (100) surface employing the SILAR method. The QDs nucleated by SILAR are crystalline structures characterized by a truncated pyramidal shape, with nucleation occurring preferentially along the rutile (010) and (001) crystal orientations. The PbS QD size distribution is constrained by lattice mismatch causing strain in the lead sulfide. These results highlight the potential of SILAR for the facile growth of high-quality epitaxial nanostructures in liquid phase, under ambient conditions and at room temperature.
Highlights
The epitaxial growth of nanocrystals onto semiconductor surfaces represents an appealing path towards the integration of quantum dots (QDs) in optoelectronic devices
The lattice mismatch determines whether epitaxial QD nucleation is feasible: (i) if there is little-to-no lattice mismatch between deposited material and substrate, the epitaxial growth provides at crystalline thin lms, the so-called Frank-van der Merwe (FM) growth, characteristic for homo-junctions, for example; (ii) as the lattice mismatch between deposited material and substrate increases, QD nucleation occurs in the socalled Volmer–Weber (VW) and Stranski–Krastanov (SK) growth regimes, which can be experimentally distinguished by the absence or presence, respectively, of a wetting layer underneath the nucleated QDs
We focus our analysis on the crystallographic QDsubstrate lattice mismatch
Summary
The epitaxial growth of nanocrystals onto semiconductor surfaces represents an appealing path towards the integration of quantum dots (QDs) in optoelectronic devices.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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.
