||~ 1.1 eV (indirect)
||Hafnium selenide, Bis(selanylidene)hafnium
|Classification / Family
Transition metal dichalcogenides (TMDCs), 2D Semiconductor materials, Nano-electronics, Nano-photonics, Photovoltaic, Materials science
||Synthetic - Chemical Vapour transport (CVT)
||Dark brown powder
In bulk form, Hafnium diselenide (HfSe2) crystallises in the layered 1T structure, with transition metal hafnium octahedrally-coordinated to six selenide chalcogenide atoms.
2D semiconductor HfSe2 is increasing in popularity for use in electronic devices due to the existence of natively-compatible HfO2 with desirable high-κ dielectrics. It is one of the first 2D materials to emulate the technologically-relevant properties of silicon (whilst enabling lower operation power than possible with silicon and its silicon oxide insulator) on a atomically-thin and smaller circuit.
Hf-based TMDs are small bandgap semiconductors possessing large work functions and reasonably high mobility. They are suitable for photovoltaic and FET applications. Ultrathin nanosheets of HfSe2 can also be built into ultrafast and ultrasensitive phototransistor devices.
Hafnium diselenide powder is obtained via the CVT method, with a purity in excess of 99.995% achieved.
Hafnium diselenide powder is suitable for liquid chemical exfoliation to prepare HfSe2 nanosheets and nanoparticles down to few-layer films. HfSe2 powder is also used for preparation of mono-layer and few-layer films via chemical vapour deposition (CVD).
Literature and Reviews
Electrical characterization of multilayer HfSe2 field-effect transistors on SiO2 substrate, M. Kang et al., Appl. Phys. Lett. 106, 143108 (2015); DIO: 10.1063/1.4917458.
Ultrafast and ultrasensitive phototransistors based on few-layered HfSe2, L. Yin et al., Appl. Phys. Lett. 109, 213105 (2016); DIO: 10.1063/1.4968808.
Device Performance Assessment of Monolayer HfSe2: A New Layered Material Compatible With High-k HfO2, A. AlMutairi et al., IEEE Electron Device Lett., , 39 (11), 1772-1775 (2018); DIO: 10.1109/LED.2018.2867957.
HfSe2 Thin Films: 2D Transition Metal Dichalcogenides Grown by Molecular Beam Epitaxy, R. Yue et al., ACS Nano, 9 (1), 474–480 (2015); DOI: 10.1021/nn5056496.
Electronic and mechanical responses of two-dimensional HfS2, HfSe2, ZrS2, and ZrSe2 from first-principles, M. Salavati, Front. Struct. Civ. Eng., 13(2): 486–494 (2019); DIO: 10.1007/s11709-018-0491-5.