Issue 22, 2014

Enhancing photo-induced ultrafast charge transfer across heterojunctions of CdS and laser-sintered TiO2 nanocrystals

Abstract

Enhancing the charge transfer process in nanocrystal sensitized solar cells is vital for the improvement of their performance. In this work we show a means of increasing photo-induced ultrafast charge transfer in successive ionic layer adsorption and reaction (SILAR) CdS–TiO2 nanocrystal heterojunctions using pulsed laser sintering of TiO2 nanocrystals. The enhanced charge transfer was attributed to both morphological and phase transformations. At sufficiently high laser fluences, volumetrically larger porous networks of the metal oxide were obtained, thus increasing the density of electron accepting states. Laser sintering also resulted in varying degrees of anatase to rutile phase transformation of the TiO2, producing thermodynamically more favorable conditions for charge transfer by increasing the change in free energy between the CdS donor and TiO2 acceptor states. Finally, we report aspects of apparent hot electron transfer as a result of the SILAR process which allows CdS to be directly adsorbed to the TiO2 surface.

Graphical abstract: Enhancing photo-induced ultrafast charge transfer across heterojunctions of CdS and laser-sintered TiO2 nanocrystals

Article information

Article type
Paper
Submitted
21 Jan 2014
Accepted
14 Apr 2014
First published
14 Apr 2014

Phys. Chem. Chem. Phys., 2014,16, 10669-10678

Author version available

Enhancing photo-induced ultrafast charge transfer across heterojunctions of CdS and laser-sintered TiO2 nanocrystals

B. T. Spann, S. V. Bhat, Q. Nian, K. M. Rickey, G. J. Cheng, X. Ruan and X. Xu, Phys. Chem. Chem. Phys., 2014, 16, 10669 DOI: 10.1039/C4CP01298D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements