jz0c00653_si_001.pdf (1.74 MB)
Enhanced Emission of Deep Ultraviolet Light-Emitting Diodes through Using Work Function Tunable Cu Nanowires as the Top Transparent Electrode
journal contribution
posted on 2020-03-18, 12:06 authored by Zongxing Huang, Zhibai Zhong, Huachun Wang, Shiqiang Lu, Jun Wang, Guozhen Liu, Tongbo Wei, Jianchang Yan, Jung-Hong Min, Woo Lim Jeong, Dong-Seon Lee, Xuefen Cai, Fuchun Xu, Xiaohong Chen, Duanjun Cai, Junxi Wang, Junyong KangDeep
ultraviolet light-emitting diodes (DUV LEDs) (<280 nm)
have been important light sources for broad applications in, e.g.,
sterilization, purification, and high-density storage. However, the
lack of excellent transparent electrodes in the DUV region remains
a challenging issue. Here, we demonstrate an architectural engineering
scheme to flexibly tune the work function of Cu@shell nanowires (NWs)
as top transparent electrodes in DUV LEDs. By fast encapsulation of
shell metals on Cu NWs and a shift of electron binding energy, the
electronic work function could be widely tailored down to 4.37 eV
and up to 5.73 eV. It is revealed that the high work function of Cu@Ni
and Cu@Pt NWs could overcome the interfacial barrier to p-AlGaN and
achieve direct ohmic contact with high transparency (91%) in 200–400
nm. Completely transparent DUV LED chips are fabricated and successfully
lighted with sharp top emission (wall-plug efficiency reaches 3%)
under a turn-on voltage of 6.4 V. This architectural strategy is of
importance in providing highly transparent ohmic electrodes for optoelectronic
devices in broad wavelength regions.