Exciton localization and ultralow onset ultraviolet emission in ZnO nanopencils-based heterojunction diodes.
n-GaN/i-ZnO/p-GaN double heterojunction diodes were constructed by vertically binding p-GaN wafer on the tip of ZnO nanopencil arrays grown on n-GaN/sapphire substrates. An increased quantum confinement in the tip of ZnO nanopencils has been verified by photoluminescence measurements combined with quantitative analyses. Under forward bias, a sharp ultraviolet emission at ~375 nm due to localized excitons recombination can be observed in ZnO. The electroluminescence mechanism of the studied diode is tentatively elucidated using a simplified quantum confinement model. Additionally, the improved performance of the studied diode featuring an ultralow emission onset, a good operation stability and an enhanced ultraviolet emission shows the potential of our approach. This work provides a new route for the design and development of ZnO-based excitonic optoelectronic devices.
Junyan
J
Jiang
Yuantao
Y
Zhang
Chen
C
Chi
Yan
Y
Long
Xu
X
Han
Bin
B
Wu
Baolin
B
Zhang
Guotong
G
Du