Abstract
We study the structure of electronic states in individual PbS nanocrystal quantum dots by scanning tunneling spectroscopy (STS) using one-to-two monolayer nanocrystal films treated with 1, 2-ethanedithiols (EDT). Up to six individual valence and conduction band states are resolved for a range of quantum dot sizes. The measured states' energies are in good agreement with calculations using the k·p four-band envelope function formalism. A comparison of STS and optical absorption spectra indicates that some of the absorption features can only be explained by asymmetric transitions involving the states of different symmetries (e.g., S and P or P and D), which points towards the relaxation of the parity selection rules in these nanostructures. STS measurements also reveal a midgap feature, which is likely similar to one observed in previous charge transport studies of EDT-treated quantum dot films.
| Original language | English |
|---|---|
| Article number | 127406 |
| Journal | Physical Review Letters |
| Volume | 110 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - Mar 22 2013 |
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ASJC Scopus subject areas
- Physics and Astronomy(all)
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Measurement of electronic states of PbS nanocrystal quantum dots using scanning tunneling spectroscopy : The role of parity selection rules in optical absorption. / Diaconescu, Bogdan; Padilha, Lazaro A.; Nagpal, Prashant; Swartzentruber, Brian S.; Klimov, Victor I.
In: Physical Review Letters, Vol. 110, No. 12, 127406, 22.03.2013.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Measurement of electronic states of PbS nanocrystal quantum dots using scanning tunneling spectroscopy
T2 - The role of parity selection rules in optical absorption
AU - Diaconescu, Bogdan
AU - Padilha, Lazaro A.
AU - Nagpal, Prashant
AU - Swartzentruber, Brian S.
AU - Klimov, Victor I
PY - 2013/3/22
Y1 - 2013/3/22
N2 - We study the structure of electronic states in individual PbS nanocrystal quantum dots by scanning tunneling spectroscopy (STS) using one-to-two monolayer nanocrystal films treated with 1, 2-ethanedithiols (EDT). Up to six individual valence and conduction band states are resolved for a range of quantum dot sizes. The measured states' energies are in good agreement with calculations using the k·p four-band envelope function formalism. A comparison of STS and optical absorption spectra indicates that some of the absorption features can only be explained by asymmetric transitions involving the states of different symmetries (e.g., S and P or P and D), which points towards the relaxation of the parity selection rules in these nanostructures. STS measurements also reveal a midgap feature, which is likely similar to one observed in previous charge transport studies of EDT-treated quantum dot films.
AB - We study the structure of electronic states in individual PbS nanocrystal quantum dots by scanning tunneling spectroscopy (STS) using one-to-two monolayer nanocrystal films treated with 1, 2-ethanedithiols (EDT). Up to six individual valence and conduction band states are resolved for a range of quantum dot sizes. The measured states' energies are in good agreement with calculations using the k·p four-band envelope function formalism. A comparison of STS and optical absorption spectra indicates that some of the absorption features can only be explained by asymmetric transitions involving the states of different symmetries (e.g., S and P or P and D), which points towards the relaxation of the parity selection rules in these nanostructures. STS measurements also reveal a midgap feature, which is likely similar to one observed in previous charge transport studies of EDT-treated quantum dot films.
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U2 - 10.1103/PhysRevLett.110.127406
DO - 10.1103/PhysRevLett.110.127406
M3 - Article
AN - SCOPUS:84875436969
VL - 110
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 12
M1 - 127406
ER -