Investigation of Nano‐Gaps in Fractured β‐Ga2O3 Nanomembranes Formed by Uniaxial Strain

Abstract

AbstractA free‐standing β‐Ga2O3, also called β‐Ga2O3 nanomembrane (NM), is an important next‐generation wide bandgap semiconductor that can be used for myriad high‐performance future flexible electronics. However, details of structure‐property relationships of β‐Ga2O3 NM under strain conditions have not yet investigated. In this paper, the electrical properties of β‐Ga2O3 NM under different uniaxial strain conditions using various surface analysis methods are systematically investigated and layer‐delamination and fractures are revealed. The electrical characterization shows that the presence of nanometer‐sized gaps between fractured pieces in β‐Ga2O3 NM causes a severe property degradation due to higher resistance and uneven charge distribution in β‐Ga2O3 NM which is also confirmed by the multiphysics simulation. Interestingly, the degraded performance in β‐Ga2O3 NM is substantially recovered by introducing excessive OH‐bonds in fractured β‐Ga2O3 NM via the water vapor treatment. The X‐ray photoelectron spectroscopy study reveals that a formation of OH‐bonds by the water vapor treatment chemically connects nano‐gaps. Thus, the treated β‐Ga2O3 samples exhibit reliable and stable recovered electrical properties up to ≈90% of their initial values. Therefore, this result offers a viable route for utilizing β‐Ga2O3 NMs as a next‐generation material for a myriad of high‐performance flexible electronics and optoelectronic applications.