Presentation Information
[25p-12H-3]Evaluating Energy Band Structure of Layered Carbon Nitride Films
〇Hitoe Habuchi1, Tomoki Hiroi1, Mari Kawashima1, Gosian Huai1 (1.NIT, Gifu College)
Keywords:
carbon nitride,ultraviolet photoelectron spectroscopy,low energy inverse photoelectron spectroscopy
Layered carbon nitride (CN), also called graphitic carbon nitride, is a two-dimensional layered crystal of nitrogen and carbon that has photocatalytic properties and is attracting attention as a new semiconductor with a band gap of approximately 2.8 eV. We have investigated the energy band structure of CN thin films synthesized by heating a substrate and raw melamine in a tube furnace.
The optical gap was estimated to be 2.8 eV from a Tautz plot. The activation energy was determined to be 0.5-0.7 eV from the temperature dependence of electrical conduction from room temperature to 200°C . The HOMO and LUMO energy with respect to vacuum level were respectively -6.9 and -3.6 eV obtained by PYS, UPS, and LEIPS, suggesting that the Fermi level was shifted from the band gap center. Thus, the band gap was estimated to be 3.3 eV. The Fermi level was 0.7 eV below the LUMO, which is close to the activation energy calculated from the temperature dependence of electrical conduction. This suggests that the CN film is an n-type semiconductor.
The optical gap was estimated to be 2.8 eV from a Tautz plot. The activation energy was determined to be 0.5-0.7 eV from the temperature dependence of electrical conduction from room temperature to 200°C . The HOMO and LUMO energy with respect to vacuum level were respectively -6.9 and -3.6 eV obtained by PYS, UPS, and LEIPS, suggesting that the Fermi level was shifted from the band gap center. Thus, the band gap was estimated to be 3.3 eV. The Fermi level was 0.7 eV below the LUMO, which is close to the activation energy calculated from the temperature dependence of electrical conduction. This suggests that the CN film is an n-type semiconductor.