Controlling the preferred orientation of layered BiOI solar absorbers
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Bismuth oxyiodide (BiOI) has gained attention for photovoltaics, photocatalysis and photodetectors owing to its composition of non-toxic elements, tolerance to point defects, and highly-suitable optical properties. But like many other bismuth-based compounds, BiOI is a layered material with anisotropic transport properties, making control over the preferred orientation critical for achieving optimal device performance. In this work, we develop new insights into the growth mechanism of BiOI synthesized by chemical vapor deposition (CVD) and show how the preferred orientation can be controlled. By adjusting the precursor and substrate temperatures to tune whether or not we are in a nucleation- or growth-controlled regime, we reproducibly vary the ratio of the (001) and (110) orientations by over two orders of magnitude. As a result, we achieve highly c-axis oriented films, which leads to less shunting than a/b-axis oriented films, resulting in improved open-circuit voltages from a median value of 0.7 V (a/b-axis oriented) to 0.9 V (c-axis oriented) in BiOI solar cells. More broadly, the described mechanisms can be used to control the preferred orientation in other low-dimensional materials, which will be important for achieving improved performance across a wide variety of devices.
Date Issued
2020-06-15
Date Acceptance
2020-06-11
Citation
Journal of Materials Chemistry C, 2020, 15 jun 2020 (31), pp.10791-10797
ISSN
2050-7526
Publisher
Royal Society of Chemistry (RSC)
Start Page
10791
End Page
10797
Journal / Book Title
Journal of Materials Chemistry C
Volume
15 jun 2020
Issue
31
Copyright Statement
© The Royal Society of Chemistry 2020. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (http://creativecommons.org/licenses/by/3.0/).
License URL
Sponsor
Downing College, Cambridge
Royal Academy of Engineering
Royal Academy Of Engineering
Isaac Newton Trust
Identifier
https://pubs.rsc.org/en/content/articlelanding/2020/TC/D0TC02076A#!divAbstract
Grant Number
RF\201718\17101
RF\201718\17101
Minute 19.07(d)
Subjects
0303 Macromolecular and Materials Chemistry
0306 Physical Chemistry (incl. Structural)
0912 Materials Engineering
Publication Status
Published
Date Publish Online
2020-06-15