Solution-Based Processing of Optoelectronically Active Indium Selenide.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Layered indium selenide (InSe) offers promise for high-performance electronic and optoelectronic devices.
• Traditional liquid phase exfoliation methods often lead to contamination and degradation, compromising InSe electronic properties.

Purpose of the Study:

• To overcome limitations of traditional InSe processing methods.
• To develop a novel, surfactant-free approach for producing pristine InSe flakes and thin films.

Main Methods:

• Utilized a surfactant-free, low boiling point, deoxygenated cosolvent system for InSe processing.
• Fabricated photodetectors using the processed InSe nanosheets and thin films.

Main Results:

• Achieved minimal processing residues and structurally/chemically pristine InSe.
• Demonstrated a maximum photoresponsivity of ≈5 × 10^7 A W^-1 in individual InSe nanosheets, the highest for solution-processed monolithic semiconductors.
• Enabled the assembly of electronically percolating InSe flake arrays without posttreatment, leading to ultrahigh performance thin-film photodetectors.

Conclusions:

• The surfactant-free cosolvent system effectively preserves InSe quality and enables high-performance device fabrication.
• This approach is generalizable to other layered materials for advancing solution-processed electronics and optoelectronics.