Researchers from Zhengzhou University, the Zhengzhou University of Railway Engineering and North Minzu University has developed a new method to improve the efficiency of deep ultraviolet (DUV) microLEDs.
The researchers explain that standard DUV microLEDs suffers from serious electron leakage, and low hole injection efficiency. And the smaller they get, the more sidewall defects reduce the efficiency even further. The researchers introduced polarized bulk charges into the hole supply layer and the electron supply layer (p-HSL and n-ESL) to enhance the binding of carriers and increase the injection efficiency of carriers.
The researchers say that their DUV microLEDs offer increased electron concentration (by 77.93% and hole concentration (93.6%). The optical power and maximum external quantum efficiency of μLED reached 31.04 W/cm2 and 2.91% respectively, and the efficiency droop is only 2.06% at 120 A/cm2.
