Issue 44, 2018

Influence of solvent additive on the chemical and electronic environment of wide bandgap perovskite thin films

Abstract

We provide in-depth insight into the role of 1,8-diiodooctane (DIO) as a solvent additive in wide bandgap CH3NH3PbBr3 (MAPbBr3) films which results in altering the kinetics of crystal growth. A detailed experimental investigation based on structural change, electronic states and chemical analysis is carried out to determine the possible mechanism which provides the control to tune the chemical environment of the perovskite film. We experimentally verify the proposed model where iodine being a soft Lewis base has a tendency to chelate with a soft Lewis acid (lead, Pb). I–Pb chelation is evident in optical and structural studies of MAPbBr3 thin films. Ultraviolet photoelectron spectroscopy (UPS) studies demonstrate that the electronic states of perovskite thin films can be modulated with a fractional concentration of DIO in the perovskite precursor solution. Chemical analysis using high resolution XPS of perovskite films shows the lower binding energies of bromine (Br 3d) and lead (Pb 4f) with DIO additive films, and confirmed the replacement of Br with I in agreement with UPS, optical and structural studies. A prominent appearance of an additional hump next to the Pb 4f peak in the film without the DIO additive is due to metallic lead's presence in the film, which acts as a bulk trap in the perovskite film. Hence, incorporation of DIO into the perovskite precursor solution reduces the recombination centers, which enhances the performance of perovskite solar cells and light emitting diodes.

Graphical abstract: Influence of solvent additive on the chemical and electronic environment of wide bandgap perovskite thin films

Supplementary files

Article information

Article type
Paper
Submitted
06 juin 2018
Accepted
11 sept. 2018
First published
11 sept. 2018

J. Mater. Chem. C, 2018,6, 12052-12061

Influence of solvent additive on the chemical and electronic environment of wide bandgap perovskite thin films

S. Singh and D. Kabra, J. Mater. Chem. C, 2018, 6, 12052 DOI: 10.1039/C8TC02754D

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