1. Solvothermal synthesis
1. Raw material ratio
Zinc powder and selenium powder are mixed at a 1:1 molar ratio, and deionized water or ethylene glycol is added as the solvent medium 35.
2 . Reaction conditions
o Reaction temperature: 180-220°C
o Reaction time: 12-24 hours
o Pressure: Maintain the self-generated pressure in the closed reaction kettle
The direct combination of zinc and selenium is facilitated by heating to generate nanoscale zinc selenide crystals 35.
3. Post-treatment process
After the reaction, it was centrifuged, washed with dilute ammonia (80 °C), methanol, and vacuum dried (120 °C, P₂O₅). btain a powder > 99.9% purity 13.
2. Chemical vapor deposition method
1. Raw material pretreatment
o The purity of the zinc raw material is ≥ 99.99% and placed in a graphite crucible
o Hydrogen selenide gas is transported by argon gas carry6.
2 . Temperature control
o Zinc evaporation zone: 850-900°C
o Deposition zone: 450-500°C
Directional deposition of zinc vapor and hydrogen selenide by temperature gradient 6.
3 . Gas parameters
o Argon flow: 5-10 L/min
o Partial pressure of hydrogen selenide:0.1-0.3 atm
Deposition rates can reach 0.5-1.2 mm/h, resulting in the formation of 60-100 mm thick polycrystalline zinc selenide 6.
3. Solid-phase direct synthesis method
1. Raw material handling
The zinc chloride solution was reacted with the oxalic acid solution to form a zinc oxalate precipitate, which was dried and ground and mixed with selenium powder at a ratio of 1:1.05 molar 4.
2 . Thermal reaction parameters
o Vacuum tube furnace temperature: 600-650°C
o Keep warm time: 4-6 hours
Zinc selenide powder with a particle size of 2-10 μm is generated by solid-phase diffusion reaction 4.
Comparison of key processes
|
method |
Product topography |
Particle size/thickness |
Crystallinity |
Fields of application |
|
Solvothermal method 35 |
Nanoballs/rods |
20-100 nm |
Cubic sphalerite |
Optoelectronic devices |
|
Vapor deposition 6 |
Polycrystalline blocks |
60-100 mm |
Hexagonal structure |
Infrared optics |
|
Solid-phase method 4 |
Micron-sized powders |
2-10 μm |
Cubic phase |
Infrared material precursors |
Key points of special process control: the solvothermal method needs to add surfactants such as oleic acid to regulate the morphology 5, and the vapor deposition requires the substrate roughness to be < Ra20 to ensure the uniformity of deposition 6.
1. Physical vapor deposition (PVD).
1 . Technology Path
o Zinc selenide raw material is vaporized in a vacuum environment and deposited onto the substrate surface using sputtering or thermal evaporation technology12.
o The evaporation sources of zinc and selenium are heated to different temperature gradients (zinc evaporation zone: 800–850 °C, selenium evaporation zone: 450–500 °C), and the stoichiometric ratio is controlled by controlling the evaporation rate12。
2 . Parameter control
o Vacuum: ≤1×10⁻³ Pa
o Basal temperature: 200–400°C
o Deposition rate:0.2–1.0 nm/s
Zinc selenide films with a thickness of 50–500 nm can be prepared for use in infrared optics 25.
2. Mechanical ball milling method
1. Raw material handling
o Zinc powder (purity≥99.9%) is mixed with selenium powder at a 1:1 molar ratio and loaded into a stainless steel ball mill jar 23.
2 . Process parameters
o Ball grinding time: 10–20 hours
Speed : 300–500 rpm
o Pellet ratio: 10:1 (zirconia grinding balls).
Zinc selenide nanoparticles with a particle size of 50–200 nm were generated by mechanical alloying reactions, with a purity of >99% 23.
3. Hot pressing sintering method
1 . Precursor preparation
o Zinc selenide nanopowder (particle size < 100 nm) synthesized by solvothermal method as raw material 4.
2 . Sintering parameters
o Temperature: 800–1000°C
o Pressure: 30–50 MPa
o Keep warm: 2–4 hours
The product has a density of > 98% and can be processed into large-format optical components such as infrared windows or lenses 45.
4. Molecular beam epitaxy (MBE).
1. Ultra-high vacuum environment
o Vacuum: ≤1×10⁻⁷ Pa
o The zinc and selenium molecular beams precisely control the flow through the electron beam evaporation source6.
2. Growth parameters
o Base temperature: 300–500°C (GaAs or sapphire substrates are commonly used).
o Growth rate:0.1–0.5 nm/s
Single-crystal zinc selenide thin films can be prepared in the thickness range of 0.1–5 μm for high-precision optoelectronic devices56.
Post time: Apr-23-2025