Amorphous Transparent Cu(S,I) Thin Films with Very High Hole Conductivity

• Published in: The journal of physical chemistry letters 2023-07, Vol.14 (26), p.6163-6169
• Main Authors: Geng, Fangjuan, Wu, Yu-Ning, Splith, Daniel, Wang, Liangjun, Kang, Xiaowan, Chen, Xiaojian, Guo, Pengsheng, Liang, Shanshan, Yang, Lei, Lorenz, Michael, Grundmann, Marius, Zhu, Jiaqi, Yang, Chang
• Format: Article
• Language: English
• Subjects: Physical Insights into Materials and Molecular Properties
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.3c01072

Amorphous transparent conductors (a-TCs) are key materials for flexible and transparent electronics but still suffer from poor p-type conductivity. By developing an amorphous Cu­(S,I) material system, record high hole conductivities of 103–104 S cm–1 have been achieved in p-type a-TCs. These high conductivities are comparable with commercial n-type TCs made of indium tin oxide and are 100 times greater than any previously reported p-type a-TCs. Responsible for the high hole conduction is the overlap of large p-orbitals of I– and S2– anions, which provide a hole transport pathway insensitive to structural disorder. In addition, the bandgap of amorphous Cu­(S,I) can be modulated from 2.6 to 2.9 eV by increasing the iodine content. These unique properties demonstrate that the Cu­(S,I) system holds great potential as a promising p-type amorphous transparent electrode material for optoelectronics.