Water adsorption enhances electrical conductivity in transparent p-type CuI

CuI has been recently rediscovered as a p-type transparent conductor with a high figure of merit. Even though many metal iodides are hygroscopic, the effect of moisture on the electrical properties of CuI has not been clarified. In this work, we observe a 2-fold increase in the conductivity of CuI after exposure to ambient humidity for 5 h, followed by slight long-term degradation. Simultaneously, the work function of CuI decreases by almost 1 eV, which can explain the large spread in the previously reported work function values. The conductivity increase is partially reversible and is maximized at intermediate humidity levels. On the basis of the large intragrain mobility measured by THz spectroscopy, we suggest that hydration of grain boundaries may be beneficial for the overall hole mobility.

Metadaten
Author details:	Andrea Crovetto ORCiD GND, Hannes Hempel ORCiD GND, Marin Rusu ORCiD, Leo Choubrac ORCiD, Sandrino Danny Kojda ORCiD GND, Klaus Habicht ORCiD GND, Thomas Unold ORCiD
DOI:	https://doi.org/10.1021/acsami.0c11040
ISSN:	1944-8244
ISSN:	1944-8252
Pubmed ID:	https://pubmed.ncbi.nlm.nih.gov/33059445
Title of parent work (English):	ACS applied materials & interfaces
Publisher:	American Chemical Society
Place of publishing:	Washington, DC
Publication type:	Article
Language:	English
Date of first publication:	2020/10/15
Publication year:	2020
Release date:	2023/10/09
Tag:	CuI; conductivity; copper iodide; humidity; p-type; transparent conductors; work function
Volume:	12
Issue:	43
Number of pages:	7
First page:	48741
Last Page:	48747
Funding institution:	European Union's Horizon 2020 research and innovation program under the; Marie Sklodowska-Curie [840751]
Organizational units:	Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie
DDC classification:	5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik
Peer review:	Referiert