Low-operation voltage of InGaN/GaN light-emitting diodes by using a Mg-doped Al0.15Ga0.85N/GaN superlattice

Low-resistivity Mg-doped Al0.15Ga0.85N/GaN strained-layer superlattices were grown. In these superlattices, the maximum hole concentration is 3 x 10(18)/cm(3) at room temperature. Hall-effect measurements indicate high conductivity of this structure in which the high activation efficiency is attributed to the strain-induced piezoelectric fields. This work also fabricated InGaN/GaN blue LEDs that consist of a Mg-doped Al0.15Ga0.85N/GaN SLs. Experimental results indicate that the LEDs can achieve a lower operation voltage of around 3 V, i.e., smaller than conventional devices which have an operation voltage of about 3.8 V.