Polarization Induced High Al Composition AlGaN p–n Junction Grown on Silicon Substrates

Wide bandgap AlGaN (x=0.7–1) p-n junction is realized on a silicon substrate through polarization induced doping. Polarization induced positive charge field is produced by linearly grading from AlN to Al_0.7Ga_0.3N, and negative charge field is generated by an inverted grading from Al_0.7Ga_0.3N to AlN. The polarization charge field induced hole density is on the order of 10¹⁸ cm^?3 in the graded Al_xGa_1?xN:Be (x=0.7–1) p-n junction. Polarization doping provides a feasible way to mass produce III-nitride devices on silicon substrates.