GaAs1-y-zPyBiz, an alternative reduced band gap alloy system lattice-matched to GaAs

The growth and properties of alloys in the alternative quaternary alloy system GaAs1-y-zPyBizwere explored. This materials system allows simultaneous and independent tuning of lattice constant and band gap energy, Eg, over a wide range for potential near- and mid-infrared optoelectronic applications by adjusting y and z in GaAs1-y-zPyBiz. Highly tensile-strained, pseudomorphic films of GaAs1-yPywith a lattice mismatch strain of ∼1.2% served as the host for the subsequent addition of Bi. Lattice-matched alloy materials to GaAs were generated by holding y ∼ 3.3z in GaAs1- y- zPyBiz. Epitaxial films with both high Bi content, z ∼ 0.0854, and a smooth morphology were realized with measured band gap energies as low as 1.11-1.01 eV, lattice-matched to GaAs substrates. Density functional theory calculations are used to provide a predictive model for the band gap of GaAs1-y-zPyBizlattice-matched to GaAs.

Duke Scholars

Author April S. Brown Electrical and Computer Engineering