High performance solar blind ultraviolet photodetector for Space Object Detection

Prixarc proposes to develop and commercialize ultraviolet C (UVC) and vacuum ultraviolet (VUV) detectors with very high responsivity and UV-visible rejection ratio coupled with very low dark current. The sensor design involves an innovative two-dimensional electron gas interdigitated channels separated by semi-insulating and metal nanoparticle functionalized ultrawide bandgap Aluminum Gallium Nitride (AlGaN) layer, in a suspended geometry. The usage of III-Nitride layers offers high temperature stability and bandgap tunability for highly efficient detection in the UVC and vacuum UV (VUV) region, while the utilization of the 2DEG IDT structure enables very low dark current and offers much higher UV absorption compared to a metal IDT. The suspended element ensures that the substrate (Si) does not influence the UV detection response of the device and helps to confine the charge carriers vertically. The metal NP functionalization will be utilized to significantly improve UV sensor responsivity due to plasmonic enhancement and passivate bare III-Nitride surface reducing trapping effects. The detector device will be fabricated, starting with commercial wafers with III-Nitride epitaxial layers grown on Si(111) substrate, through standard photolithographic process, with nominal device size targeted at 1 mm2. Standard fabrication process developed by the team will be utilized involving etching, metal deposition, annealing as well as through wafer etching to release the detector element. During Phase I, we will conduct a feasibility study involving design, fabrication and characterization of the detectors in UVC and VUV regions, along with transition plan and business case analysis, to demonstrate the possibility of achieving the specified device performance objectives. The option period will involve modification in the III-Nitride epitaxial to further improve device performance.