Jun 20, 2013
Ta3N5 nanobelts configured as FET photodetectors
Tantalum (V) nitride (Ta3N5) is a semiconductor material with a band gap of 2.08 eV, just between CdS (2.53 eV) and CdSe (1.74 eV), which could serve as a sensitiser for photovoltaic cells and other optoelectronic devices. Other applications include breaking up water as a visible-light photocatalyst. Synthesis of the material as nanoparticles has been reported, but preparation of Ta3N5 nanobelts is more challenging.
One approach, being pursued by researchers from Nanjing University in China and the National Institute for Materials Science in Japan, is to synthesize Ta3N5 nanobelts by aminolysis of TaS3 nanobelt templates. Using the sample, the team has fabricated a field-effect-transistor (FET), and found that the device exhibits high ultraviolet-visible (UV-vis) photosensitive properties. The photocurrent increased by nearly 10 times the dark current under 450 nm light irradiation at an applied voltage of 5.0 V.
More information can be found in the journal Nanotechnology.
About the author
The study was conducted by two research teams from the School of Chemistry and Chemical Engineering at Nanjing University in China, and the National Institute for Materials Science (NIMS) in Japan. Dr X C Wu and Y R Tao are professor and associate professor at Nanjing University, respectively. They firstly prepared and characterized the Ta3N5 super-long nanobelts at Nanjing University, and then Dr Wu took the nanobelts to visit Prof. Dr Y Bando’ s group at NIMS in 2010. Dr Wu and Dr Li accomplished the fabrication and photosensitive experiments of the nanobelt FET under the guidance of Prof. Dr Y Bando and Prof. Dr D Golberg. Now, Dr Li is working in the Department of Physics at Soochow University in China.