n-ZnO/p-GaN heterojunction light-emitting diodes featuring a buried polarization-induced tunneling junction

摘要

n-ZnO/p-GaN heterojunction light-emitting diodes with a p-GaN/Al_0.1Ga_0.9N+-GaN polarization-induced tunneling junction (PITJ) were fabricated by metal-organic chemical vapor deposition. An intense and sharp ultraviolet emission centered at ～396 nm was observed under forward bias. Compared with the n-ZnO/p-GaN reference diode without PITJ, the light intensity of the proposed diode is increased by ～1.4-folds due to the improved current spreading. More importantly, the studied diode operates continuously for eight hours with the decay of only ～3.5% under 20 mA, suggesting a remarkable operating stability. The results demonstrate the feasibility of using PITJ as hole injection layer for high-performance ZnO-based light-emitting devices.