Drastic difference between hole and electron injection through the gradient shell of CdxSeyZn1−xS1−y quantum dotsShow others and affiliations
2017 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 9, no 34, p. 12503-12508Article in journal (Refereed) Published
Abstract [en]
Ultrafast fluorescence spectroscopy was used to investigate the hole injection in CdxSeyZn1-xS1-y gradient core-shell quantum dot (CSQD) sensitized p-type NiO photocathodes. A series of CSQDs with a wide range of shell thicknesses was studied. Complementary photoelectrochemical cell measurements were carried out to confirm that the hole injection from the active core through the gradient shell to NiO takes place. The hole injection from the valence band of the QDs to NiO depends much less on the shell thickness when compared to the corresponding electron injection to n-type semiconductor (ZnO). We simulate the charge carrier tunneling through the potential barrier due to the gradient shell by numerically solving the Schrodinger equation. The details of the band alignment determining the potential barrier are obtained from X-ray spectroscopy measurements. The observed drastic differences between the hole and electron injection are consistent with a model where the hole effective mass decreases, while the gradient shell thickness increases.
Place, publisher, year, edition, pages
2017. Vol. 9, no 34, p. 12503-12508
National Category
Materials Chemistry Nano Technology
Identifiers
URN: urn:nbn:se:uu:diva-335189DOI: 10.1039/c7nr04495jISI: 000409215300033PubMedID: 28819669OAI: oai:DiVA.org:uu-335189DiVA, id: diva2:1163857
Note
Title in WoS: Drastic difference between hole and electron injection through the gradient shell of CdxSeyZn1-xS1-y quantum dots
2017-12-082017-12-082017-12-28Bibliographically approved