Interface quality informed by quantum-based magnetoconductivity: ITO on fused silica

Quantum magnetoconductance, delta-sigma(B)=sigma(B)-sigma(0), offers a new, unique way to study phonons in heavily-doped, complex semiconductors, including beta-Ga2O3 and Sn-doped In2O3 (ITO). At low temperature, theory predicts delta-sigma(B)=2.908B^(1/2) S/cm, shown to be true for thick, but not thin, samples. We grew ten ITO films by PLD on fused silica, d=13–292 nm. The thickness dependence was explained by a new delta-sigma(d)-vs-d theory based on a second source of disorder, interface-generated defects that decrease exponentially with distance from the ITO/FS interface. A fit of delta-sigma(d)-vs-d gives three parameters, including d*, the thickness above which the surface is not affected by interface damage.