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Abstract In this study, Si/β‐Ga₂O₃solar‐blind photodetectors (PDs) have been demonstrated via micro‐transfer printing of a single crystalline Si pillar on β‐Ga₂O₃. Unlike other previous approaches for β‐Ga₂O₃based heterojunction, this new single crystalline p‐n Si/β‐Ga₂O₃heterojunction has a particle‐free heterointerface and does not show any sign of internal strain after the heterogeneous integration that is confirmed by Raman spectroscopy. As a result, PDs exhibit extremely high photoresponsivity (748 A W⁻¹), quantum efficiency (3.67 × 10⁵%), and UV/visible rejection ratio (≈10⁵) under UV light illumination. This result is believed to provide a viable route for the realization of high‐performance solar‐blind photodetection systems, which form some of the most indispensable and important components in high‐performance next‐generation security, biomedical, and environmental monitoring systems. Also, the unique heterogeneous integration method allows us to realize a variety of β‐Ga₂O₃based heterostructures that can further enhance the optical performances of β‐Ga₂O₃based PDs. 

Abstract A free‐standing β‐Ga₂O₃, also called β‐Ga₂O₃nanomembrane (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‐Ga₂O₃NM under strain conditions have not yet investigated. In this paper, the electrical properties of β‐Ga₂O₃NM 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‐Ga₂O₃NM causes a severe property degradation due to higher resistance and uneven charge distribution in β‐Ga₂O₃NM which is also confirmed by the multiphysics simulation. Interestingly, the degraded performance in β‐Ga₂O₃NM is substantially recovered by introducing excessive OH‐bonds in fractured β‐Ga₂O₃NM 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‐Ga₂O₃samples exhibit reliable and stable recovered electrical properties up to ≈90% of their initial values. Therefore, this result offers a viable route for utilizing β‐Ga₂O₃NMs as a next‐generation material for a myriad of high‐performance flexible electronics and optoelectronic applications. 

Abstract Here, high power flexible Schottky barrier diodes (SBDs) are demonstrated on a plastic substrate using single crystalline β‐Ga₂O₃nanomembranes (NMs). In order to realize flexible high power β‐Ga₂O₃SBDs, sub‐micron thick freestanding β‐Ga₂O₃NMs are created from a bulk β‐Ga₂O₃substrate and transfer‐printed onto the plastic substrate via a microtransfer printing method. It is revealed that the material property of β‐Ga₂O₃NMs such as crystal structure, electron affinity, and bandgap remains unchanged compared with its bulk properties. Flexible β‐Ga₂O₃SBDs exhibit the record high critical breakdown field strength (E_c) of 1.2 MV cm⁻¹in the flat condition and 1.07 MV cm⁻¹ofE_cunder the bending condition. Overall, flexible β‐Ga₂O₃SBDs offer great promise for future flexible energy convergence systems and are expected to provide a much larger and more versatile platform to address a broader range of high‐performance flexible applications.