I-III-VI semiconductors

A fourth element is often added to a I-III-VI2 material to tune the bandgap for maximum solar cell efficiency.

The β form has a wurtzite-like crystal structure (space group Pna21); it is metastable, but exhibits a long-term stability at temperatures below 300 °C.

Their cleaved surfaces have lattice constants that match those of ZnO and GaN and are therefore suitable for epitaxial growth of thin films of those materials.

β-LiGaO2 is a potential nonlinear optics material, but its direct bandgap of 5.6 eV is too wide for visible light applications.

The bandgap tuning is discontinuous because ZnO and β-LiGaO2 do not mix but form a Zn2LiGaO4 phase when their ratio is between ca.

In the second stage, the melt is homogenized in a sealed quartz ampoule, which is coated inside with pyrolytic carbon to reduce Li reactivity.