Bandgap widening and behavior of Raman-active phonon modes of cubic single-crystalline (In,Ga)${}_2$O${}_3$ alloy films

Abstract

The influence of Ga incorporation into cubic In${}_2$O${}_3$ on the electronic and vibrational properties is discussed for (In${}_{1-x}$,Ga${}_x$)${}_2$O${}_3$ alloy films grown by molecular beam epitaxy. Using spectroscopic ellipsometry, a linear dependence of the absorption onset on the Ga content $x$ is found with a blueshift of up to 150 meV for $x=0.1$. Consistently, the fundamental band gap exhibits a blueshift as determined by hard X-ray photoelectron spectroscopy. The dependence of the absorption onset and the effective electron mass on the electron concentration is derived from the infrared dielectric functions for a Sn doped alloy film. The influence of alloying on phonon modes is analyzed on the basis of Raman spectroscopic measurements. The frequencies of several phonon modes are identified as sensitive measures for the spectroscopic determination of the Ga content.

References in corpus (6)

• Phase diagram and polarization of stable phases of (Ga${}_{1-x}$In${}_x$)${}_2$O${}_3$
• Optical phonon modes, static and high frequency dielectric constants, and effective electron mass parameter in cubic In${}_2$O${}_3$
• Low In solubility and band offsets in the small-$x$ $\beta$-Ga${}_2$O${}_3$/(Ga${}_{1-x}$In${}_x$)${}_2$O${}_3$ system
• Investigating the ranges of (meta)stable phase formation in (InxGa1-x)2O3: Impact of the cation coordination
• Properties of (Ga${}_{1-x}$In${}_x$)${}_2$O${}_3$ over the whole $x$ range
• Signatures of free carriers in Raman spectra of cubic In${}_2$O${}_3$

Cited by in corpus (2)

• The electrical conductivity of cubic (In${}_{1-x}$Ga${}_x$)${}_2$O${}_3$ films ($x\le 0.18$): Native point defects, Sn-doping, and the surface electron accumulation layer
• Molecular beam epitaxy of single-crystalline bixbyite (In${}_{1-x}$Ga${}_x$)${}_2$O${}_3$ films ($x\le 0.18$): Structural properties and consequences of compositional inhomogeneity