restricting the efficiency of LED

University of California, Santa Barbara (UCSB) research team claims that through the first principles calculation found that, with respect to potassium nitride (GaN)-based light-emitting diode (LED), Auger recombination (Augerrecombination) is its reduced efficiency (LEDdroop) and green gap (greengap) The main reason for the same time, unfortunately did not come up with effective solutions.

     LEDdroop refers to higher current operation, the external quantum efficiency of light-emitting diodes will decline. UCSB's KrisDelaney, PatrickRink and ChrisVandeWalle calculations show that the culprit is a decline in the efficiency of Auger recombination, which is a non-radiation type of complex acts, in the 2.5eV (corresponding to a wavelength of 0.5μm) reached its peak. This also explains the "green gap" - that is, wavelengths from the blue when you enter the green-band, LED quantum efficiency will decrease the origin.

    Earlier, LED manufacturers PhilipsLumileds claims based on the experimental results, Auger recombination is the reduced efficiency at higher current, the main reason for this non-radiative composite process involves the interaction of three carrier, which contains at least one electronic and one empty points. UCSB calculation results support this view, unlike other theoretical research team that Auger recombination can be ignored for the LEDdroop, the difference is a different band structure of nitrides: UCSB team found the second conduction band (conductionband ), and included in the calculation.