||1.3 - 2.0 eV 
|Classification / Family
Transition metal dichalcogenides (TMDCs), 2D semiconductor materials, Inorganic semiconductors, Nano-electronics, Nano-photonics, Photovoltaics
||Synthetic - Chemical Vapour Transport (CVT)
||Dark brown powder
Like black phosphorus (BP) - but with a much more stable nature under ambient conditions, ultra-thin indium selenide (InSe) offers a useful middle ground between silicon and graphene. Weak van der Waals forces between layers of InSe allow easy mechanical and liquid exfoliation, enabling naturally thin films scaling to true nanometer dimensions. With electron mobility up to 2,000 cm2 V-1 s-1 and a direct band gap of ~ 1.3 eV, InSe is a semiconductor comparable to silicon with ultra-fast electron response.
With high purity, indium selenide powder offers the opportunity to produce InSe nanosheets or nanoparticle flakes in mass quantity by liquid exfoliation without going through the chemical vapour transport method. Those exfoliated nano-flakes have been widely used for the preparation of electronic and optoelectronic devices. Transistors and photodetectors that use few-layered InSe exhibit high on/off ratios, broad-band response and ultra-fast response time.
With a layered structure, exfoliated nanosheets from Indium selenide (InSe) powder offer new opportunities for practical applications in hydrogen evolution reaction (HER), photodetectors and optical sensing, FETs and thermo-electronic devices.
Indium selenide (InSe) powder is obtained via the CVT method, with a purity in excess of 99.995% achieved.
Indium selenide (InSe) powder is suitable for liquid chemical exfoliation to prepare InSe nanosheets and nanoparticles down to few-layer films. InSe powder is also used for preparation of mono-layer and few-layer films via chemical vapour deposition (CVD).
Literature and Reviews
The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals,G. W. Mudd et al., Sci. Rep., 6:39619 (2016); DOI: 10.1038/srep39619.
High Performance and Bendable Few-Layered InSe Photodetectors with Broad Spectral Response, S. Tamalampudi et al., Nano Lett. 2014, 14, 2800−2806 (2014); doi: 10.1021/nl500817g.
Structural modification and band-gap crossover in indium selenide nanosheets, M. Airo et al., RSC Adv., 6, 40777 (2016); DOI: 10.1039/c6ra00262e.
Liquid-Phase Exfoliated Indium–Selenide Flakes and Their Application in Hydrogen Evolution Reaction, E. Petroni et al., Small, 14, 1800749 (2018); DOI: 10.1002/smll.201800749.
Evolution of the Electronic Band Structure and Efficient Photo-Detection in Atomic Layers of InSe, S. Lei et al., ACS Nano 8 (2), 1263–1272 (2014); DIO: 10.1021/nn405036u.
Tuning the Bandgap of Exfoliated InSe Nanosheets by Quantum Confinement, G. Mudd et al., Adv. Mater., 25, 5714–5718 (2013); DOI: 10.1002/adma.201302616.