Vapor phase tri-methyl-indium seeding system suitable for high temperature spectroscopy and thermometry

Area of Science:

• Combustion science
• Spectroscopy
• Chemical engineering

Background:

• Tri-methyl-indium (TMI) is a key indium precursor for introducing indium atoms into reactive environments.
• Spectroscopic diagnostics require precise control over the concentration of seeded species.

Purpose of the Study:

• To develop and calibrate a system for seeding Tri-methyl-indium (TMI) into combustion flows.
• To investigate the feasibility of using TMI for quantitative spectroscopic measurements.

Main Methods:

• A seeding system was designed to introduce TMI-laden carrier gas into an air/fuel mixture.
• Fluorescence intensity was used to calibrate TMI concentration (2-45 ppm).
• Laser-induced fluorescence and absorption spectroscopy detected indium atoms in the flame.

Main Results:

• TMI seeding showed a linear response from 3-22.5 ppm, with non-linearity above 25 ppm due to self-absorption or vapor pressure saturation.
• Molecular transitions of InH and InOH radicals were observed in the flame emission spectrum.
• Atomic indium concentration in the TMI-seeded flame was measured at the ppm level.

Conclusions:

• Seeding reactive gas flows with organometallic vapors like TMI is feasible for quantitative spectroscopic investigations.
• This technique has potential applications in chemical vapor deposition and flame temperature measurements.