Epitaxial BaSnO₃thin films with low dislocation density grown on lattice matched LaInO₃substrates

Area of Science:

• Materials Science
• Solid-State Physics
• Thin Film Deposition

Background:

• Barium stannate (BaSnO3) is a promising perovskite oxide semiconductor with high electrical conductivity.
• Epitaxial growth of high-quality BaSnO3 thin films is crucial for device applications.
• Finding suitable substrates for epitaxial growth remains a challenge.

Purpose of the Study:

• To investigate lanthanum indium oxide (LaInO3) with (110) surface orientation as a novel substrate for BaSnO3 thin film growth.
• To optimize the substrate surface for improved epitaxial film quality.
• To characterize the structural and electrical properties of the grown BaSnO3 films.

Main Methods:

• Pulsed laser deposition (PLD) for thin film growth.
• Reflection high-energy electron diffraction (RHEED) for surface ordering.
• Energy dispersive X-ray analysis (EDX) and inductively coupled plasma-optical emission spectrometry (ICP-OES) for composition.
• Transmission electron microscopy (TEM) for structural analysis.
• Hall effect measurements for electrical properties.

Main Results:

• Slight barium (Ba) doping of LaInO3 stabilized the substrate surface, facilitating well-ordered BaSnO3 epitaxial growth.
• Negligible lattice mismatch between BaSnO3 and Ba-doped LaInO3 resulted in fully strained BaSnO3 films without misfit dislocations.
• BaSnO3 films exhibited a Hall mobility of 69 cm2V−1s−1 at room temperature and 99 cm2V−1s−1 at 20 K, with a carrier density of 3.8 × 1019 cm−3.

Conclusions:

• Barium-doped LaInO3 (110) is a viable and effective substrate for the epitaxial growth of semiconducting BaSnO3 thin films.
• The developed method yields high-quality, strained BaSnO3 films with excellent electrical conductivity.
• This research opens avenues for advanced oxide semiconductor device fabrication.