Influence of hydrogen incorporation on conductivity and work function of VO2 nanowires

Autor: Young Jin Choi, Won G. Hong, Hyun-Seok Jang, Jeong Young Park, Gyu-Tae Kim, Jun Woo Jeon, Jae-Eun Kim, Jung Yeol Shin, Hae Jin Kim, Jonghyurk Park, Junhee Choi, Byung Hoon Kim
Rok vydání: 2019
Předmět:
Zdroj: Nanoscale. 11:4219-4225
ISSN: 2040-3372
2040-3364
DOI: 10.1039/c9nr00245f
Popis: We report improved conductance by reducing the work function via incorporation of hydrogen into VO2 nanowires. The VO2 nanowires were prepared using the chemical vapor deposition method with V2O5 powder on silicon substrates at 850 °C. Hydrogenation was carried out using the high-pressure hydrogenation method. Raman spectroscopy confirmed that the incorporated hydrogen atoms resulted in a change in the lattice constant of the VO2 nanowires (NWs). To quantitatively measure the work function of the nanowires, Kelvin probe force microscopy (KPFM) was employed at ambient conditions. We found that the work function decreased with increasing H2 pressure, which also resulted in increased conductance. This is associated with hydrogen diffused into the VO2 that acts as a donor to elevate the Fermi level, which was also confirmed by KPFM. From these results, tuning of the reversible electrical properties of VO2 NWs, including the conductance and work function, can be achieved by incorporating hydrogen at relatively moderate temperatures.
Databáze: OpenAIRE