Epitaxial growth of polarization-graded AlGaN-based solar-blind ultraviolet photodetectors on pre-grown AlN templates

Abstract In this letter, based on the method of introducing one mesothermal AlN (MT-AlN) interlayer, a high-quality AlN template is firstly obtained by adjusting the growth rate of the high-temperature AlN (HT-AlN) epilayers on both sides of the MT-AlN interlayer. Then, the epitaxial growth of polarization-graded AlGaN-based solar-blind ultraviolet photodetector (SUV-PD) structural material is implemented on the pre-grown AlN template by introducing an n-AlxGa1−xN gradient layer. It leads to the elimination of band discontinuity and forms a polarization-graded induced field resulting in a high-performance back-illuminated AlGaN-based SUV-PD. This research provides an important reference for the development of high-performance back-illuminated AlGaN-based SUV-PDs.