Issue 37, 2015

Hybrid zinc oxide/graphene electrodes for depleted heterojunction colloidal quantum-dot solar cells

Abstract

Recently, hybrid nanocomposites consisting of graphene/nanomaterial heterostructures have emerged as promising candidates for the fabrication of optoelectronic devices. In this work, we have employed a facile and in situ solution-based process to prepare zinc oxide/graphene quantum dots (ZnO/G QDs) in a hybrid structure. The prepared hybrid dots are composed of a ZnO core, with an average size of 5 nm, warped with graphene nanosheets. Spectroscopic studies show that the graphene shell quenches the photoluminescence intensity of the ZnO nanocrystals by about 72%, primarily due to charge transfer reactions and static quenching. A red shift in the absorption peak is also observed. Raman spectroscopy determines G-band splitting of the graphene shell into two separated sub-bands (G+, Gāˆ’) caused by the strain induced symmetry breaking. It is shown that the hybrid ZnO/G QDs can be used as a counter-electrode for heterojunction colloidal quantum-dot solar cells for efficient charge-carrier collection, as evidenced by the external quantum efficiency measurement. Under the solar simulated spectrum (AM 1.5G), we report enhanced power conversion efficiency (35%) with higher short current circuit (80%) for lead sulfide-based solar cells as compared to devices prepared by pristine ZnO nanocrystals.

Graphical abstract: Hybrid zinc oxide/graphene electrodes for depleted heterojunction colloidal quantum-dot solar cells

Supplementary files

Article information

Article type
Paper
Submitted
20 Jun 2015
Accepted
18 Aug 2015
First published
20 Aug 2015

Phys. Chem. Chem. Phys., 2015,17, 24412-24419

Hybrid zinc oxide/graphene electrodes for depleted heterojunction colloidal quantum-dot solar cells

M. M. Tavakoli, H. Aashuri, A. Simchi and Z. Fan, Phys. Chem. Chem. Phys., 2015, 17, 24412 DOI: 10.1039/C5CP03571F

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