A Study on the Base Recombination Current in Direct-Growth npn
Abstract – We studied the impact of indium content on the base recombination current components for GaN/InGaN double-heterojunction bipolar transistors (DHBTs). With higher indium content in the base layer, the surface recombination current was reduced. The bulk recombination current, however, increases as the indium composition increases in the DHBTs. After the device burn-in, the GaN/In0.05Ga0.95N DHBT demonstrated the current gain (hfe) > 84 and collector current density (JC) > 6.75kA/cm2. This result stands as one of the highest performance reported on directgrowth GaN/InGaN DHBTs grown on sapphire substrates.
Keywords: InGaN, GaN, HBT, recombination, directgrowth