Effect of Oxygen on the Electrical Conductivity of Pt-Contacted α-Ga2O3/ε(κ)-Ga2O3 MSM Structures on Patterned Sapphire Substrates

Electrical conductivity and gas sensitivity of alpha-Ga2O3/epsilon (kappa)-Ga2O3 structures were measured for oxygen concentrations ranging from 2 % to 100 % and temperatures ranging from 25 degrees C to 220 degrees C. It was found that the oxygen sensitivity of the structures depended on the donor dopant concentration. The alpha-Ga2O3/epsilon(kappa)-Ga2O3 structures doped with similar to 1.5 x 10(17) cm(-3) of Sn showed high sensitivity to O-2 in the temperature range from 180 degrees C to 220 degrees C and at the bias voltage below 7.5 V. This effect can be attributed to the chemisorption of oxygen molecules on the surface of structures, which reduces energy barriers between epsilon(k)-Ga2O3 grains.

Automated summary

The electrical conductivity and gas sensitivity of alpha-Ga2O3/epsilon (kappa)-Ga2O3 structures were measured at various oxygen concentrations and temperatures. It was observed that the oxygen sensitivity of the structures depended on the donor dopant concentration. Structures doped with a specific amount of Sn showed high sensitivity to O2 at certain temperatures and bias voltages, attributed to the chemisorption of oxygen molecules on the surface reducing energy barriers between epsilon (kappa)-Ga2O3 grains.