Cube-Shaped GaN UV Photodetectors Using 3D-Printed Panels for Omnidirectional Detection

In this study, we designed and developed a hexahedral ultraviolet (UV) photodetector using three-dimensional (3D) printing. Furthermore, we demonstrated the proposed photodetector's functionality (omnidirectional UV detection) using photosensitive gallium nitride (GaN). To fabricate the cube (regular hexahedron), six panels were separately 3D-printed; a GaN UV photodetector was then mounted onto each panel during assembly. Given that the hexahedral photodetector had six sensors, the change in current for each sensor was distinct based on the angle of incidence of UV light; consequently, the UV source could be easily traced. Compared to conventional solar sensors, the proposed novel photodetector could estimate the various locations of the UV source through selective activation and deactivation. Optical and electrical characterization revealed high absorption of the UV spectra (near 370 nm), high signal-to-noise values (47-70), and rapid response times (0.4-0.8 s). This study demonstrates the feasibility of the design and fabrication-using 3D printing technology-of optical sensors for the multiple detection of incident UV light during navigation in various environments such as outer space, oceans, and subterranean environments.