Breaking the carrier injection bottleneck of phosphor-free nanowire white light-emitting diodes.
We have examined the carrier injection process of axial nanowire light-emitting diode (LED) structures and identified that poor carrier injection efficiency, due to the large surface recombination, is the primary cause for the extremely low output power of phosphor-free nanowire white LEDs. We have further developed InGaN/GaN/AlGaN dot-in-a-wire core-shell white LEDs on Si substrate, which can break the carrier injection efficiency bottleneck, leading to a massive enhancement in the output power. At room temperature, the devices can exhibit an output power of ~1.5 mW, which is more than 2 orders of magnitude stronger than nanowire LEDs without shell coverage. Additionally, such phosphor-free nanowire white LEDs can deliver an unprecedentedly high color rendering index of ~92-98 in both the warm and cool white regions, with the color rendering capability approaching that of an ideal light source, i.e. a blackbody.
Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada.
Hieu Pham Trung
HP
Nguyen
Shaofei
S
Zhang
Ashfiqua T
AT
Connie
Md Golam
MG
Kibria
Qi
Q
Wang
Ishiang
I
Shih
Zetian
Z
Mi