Persistent Photoconductivity in High-mobility Al{sub}xGa{sub}(1-x)N/AlN/GaN Heterostructures Grown by Metal-organic Vapor-phase Epitaxy

摘要

We report on the persistent photoconductivity (PPC) effect in Al{sub}xGa{sub}(1-x)N/AlN/GaN heterostructures with two different Al compositions (x=0.15 and 0.25). The two-dimensional electron gas (2DEG) was characterized by Shubnikov-de Haas and Hall measurements. At cryogenic temperatures under optical illumination, the 2DEG carrier density and mobility was enhanced. The persistent photocurrent in both samples exhibited a strong dependence on illumination wavelength.