AI Article Synopsis
- Rock-salt lead selenide (PbSe) nanocrystals can be organized into large-scale square superlattices by assembling them at a liquid-air interface and then connecting them through oriented attachment.
- Scanning Tunneling Spectroscopy (STS) reveals insights into the electronic properties of these superlattices, allowing for the analysis of the band gap and electronic states after controlled annealing.
- The study finds that while the connections between the nanocrystals enhance electronic coupling, the overall electronic structure is still heavily affected by disorder and variability in the system.
Article Abstract
Rock-salt lead selenide nanocrystals can be used as building blocks for large scale square superlattices via two-dimensional assembly of nanocrystals at a liquid-air interface followed by oriented attachment. Here we report Scanning Tunneling Spectroscopy measurements of the local density of states of an atomically coherent superlattice with square geometry made from PbSe nanocrystals. Controlled annealing of the sample permits the imaging of a clean structure and to reproducibly probe the band gap and the valence hole and conduction electron states. The measured band gap and peak positions are compared to the results of optical spectroscopy and atomistic tight-binding calculations of the square superlattice band structure. In spite of the crystalline connections between nanocrystals that induce significant electronic couplings, the electronic structure of the superlattices remains very strongly influenced by the effects of disorder and variability.
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| http://dx.doi.org/10.1088/1361-6528/abfd57 | DOI Listing |
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