High Stability Flexible Deep-UV Detector Based on All-Oxide Heteroepitaxial Junction

Abstract

Transparent flexible electronics constitute a significant research field. Flexible deep-ultraviolet (UV) detectors have received much attention due to their potential in the applications of healthcare, communications, astronomy, and environment monitoring. Recent studies have investigated a variety of flexible photodetectors but show that the transparent, flexible, chemical, and thermal stability performances of these detectors cannot meet the requirements for practical applications. In this study, we demonstrate transparent flexible deep-UV detectors based on the combination of high-quality epitaxial n-type β-Ga2O3 and p-type NiO films as a photodiode on a flexible muscovite substrate. The electrical current of this heterojunction is increased over a 1000 times for on/off ratio under 265 nm wavelength illumination with a reasonable response (<1 s). Moreover, these photodetectors also exhibit good thermal stability as well as excellent mechanical flexibility. Our results exhibit the superior performance of the oxide-based solar-blind deep-UV detectors for advanced flexible sensing and smart applications.

Ga2O3/GaN Heterointerface-Based Self-Driven Broad-Band Ultraviolet Photodetectors with High Responsivity

“…In the case of MgZnO/ZnO, high Mg content is required, which is challenging due to the phase segregation in a single wurtzite phase of MgZnO . On the contrary, the interface between Ga 2 O 3 and GaN, having a small lattice mismatch and a low conduction band offset, is considered a promising heterointerface for BBUV photodetection devices. , Specifically, Ga 2 O 3 is an ultrawide band-gap semiconductor (∼4.8 eV) with high breakdown voltage (breakdown field of 7–8 MV/cm) and excellent chemical and thermal stability (stable up to 1100 °C). − Further, GaN is a potentially feasible wide band-gap semiconductor (∼3.4 eV) for next-generation device applications such as high electron mobility transistors and field-effect transistors. , These advantages allow ultrawide band-gap Ga 2 O 3 to be integrated on GaN, possibly appropriate for BBUV photodetectors. , …”

Flexible gallium oxide electronics

“…In this context, it triggers more tackles in the nanofabrication processes when using flexible substrates, such as the thickness inhomogeneity for the individual layers of the multi-layer stacked structure, and the defocus problem during the patterning procedures caused by the unavoidable tension of the flexible substrates. Another research trend is the integration of Ga 2 O 3 with other semiconductor materials to create various heterostructures, therefore providing enhanced or multiple functions of the integrated devices, such as PDs with enhanced performances, self-powered PDs, and CMOS circuits [143][144][145][146]. However, in such a regime, the epitaxial ability of the flexible template for materials with varied lattice structures becomes a new challenge.…”