TY  - JOUR
A1  - Crovetto, Andrea
A1  - Hempel, Hannes
A1  - Rusu, Marin
A1  - Choubrac, Leo
A1  - Kojda, Sandrino Danny
A1  - Habicht, Klaus
A1  - Unold, Thomas
T1  - Water adsorption enhances electrical conductivity in transparent p-type CuI
JF  - ACS applied materials & interfaces
N2  - 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.
KW  - transparent conductors
KW  - CuI
KW  - copper iodide
KW  - conductivity
KW  - humidity
KW  - p-type
KW  - work function
Y1  - 2020
U6  - https://doi.org/10.1021/acsami.0c11040
SN  - 1944-8244
SN  - 1944-8252
VL  - 12
IS  - 43
SP  - 48741
EP  - 48747
PB  - American Chemical Society
CY  - Washington, DC
ER  -