Premium
Elucidating the Coordination of Diethyl Sulfide Molecules in Copper(I) Thiocyanate (CuSCN) Thin Films and Improving Hole Transport by Antisolvent Treatment
Author(s) -
Worakajit Pimpisut,
Hamada Fumiya,
Sahu Debashis,
Kidkhunthod Pinit,
Sudyoadsuk Taweesak,
Promarak Vinich,
Harding David J.,
Packwood Daniel M.,
Saeki Akinori,
Pattanasattayavong Pichaya
Publication year - 2020
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202002355
Subject(s) - materials science , thiocyanate , thin film , crystallite , copper , molecule , microstructure , chemical engineering , inorganic chemistry , nanotechnology , organic chemistry , composite material , metallurgy , chemistry , engineering
Abstract Copper(I) thiocyanate (CuSCN) is rising to prominence as a hole‐transporting semiconductor in various opto/electronic applications. Its unique combination of good hole mobility, high optical transparency, and solution‐processability renders it a promising hole‐transport layer for solar cells and p ‐type channel in thin‐film transistors. CuSCN is typically deposited from sulfide‐based solutions with diethyl sulfide (DES) being the most widely used. However, little is known regarding the effects of DES on CuSCN films despite the fact that DES can coordinate with Cu(I) and result in a different coordination polymer having a distinct crystal structure when fully coordinated. Herein, the coordination of DES in CuSCN films is thoroughly investigated with a suite of characterization techniques as well as density functional theory. This study reveals that DES directly affects the microstructure of CuSCN by stabilizing the polar crystalline surfaces via the formation of strong coordination bonds. Furthermore, a simple antisolvent treatment is demonstrated to be effective at modifying the microstructure and morphology of CuSCN films. The treatment with tetrahydrofuran or acetone leads to uniform films consisting of CuSCN crystallites with high crystallinity and their surfaces passivated by DES molecules, resulting in an increase in the hole mobility from 0.01 to 0.05 cm 2 V −1 s −1 .