PlumX Metrics
Embed PlumX Metrics

Origin of electrons emitted into vacuum from InGaN light emitting diodes

Applied Physics Letters, ISSN: 0003-6951, Vol: 105, Issue: 5
2014
  • 37
    Citations
  • 0
    Usage
  • 66
    Captures
  • 0
    Mentions
  • 0
    Social Media
Metric Options:   Counts1 Year3 Year

Metrics Details

  • Citations
    37
    • Citation Indexes
      37
  • Captures
    66

Article Description

The mechanism responsible for efficiency droop in InGaN light-emitting diodes (LEDs) has long been elusive due to indirect measurement techniques used for its identification. Auger recombination is unique among proposed efficiency droop mechanisms, in that it is the only mechanism capable of generating hot carriers. In a previous study [J. Iveland et al., Phys. Rev. Lett. 110, 177406 (2013)], we performed electron energy analysis of electrons emitted into vacuum from a forward biased InGaN LED that had been brought into negative electron affinity by cesiation. Three peaks were observed in the energy spectrum of vacuum emitted electrons. In this Letter, we unambiguously identify the origin of the peaks. The two higher energy peaks correspond to accumulation of electrons transported to the surface in the bulk Γ and side L conduction band valleys. The L-valley peak is a direct signature of a hot Auger electron population. The lower energy peak results from surface photoemission induced by the internal LED light emitted from the InGaN quantum wells. Two control experiments were performed. In the first, a simple GaN pn junction generated only a single Γ peak in electroemission. In the second, selective detection of the photoemission from an LED under modulated light excitation and DC electrical injection confirms that only the low energy peak is photogenerated and that LED light is incapable of generating Γ or L-valley peaks, the latter only occurring due to the Auger effect in the LED active region. © 2014 AIP Publishing LLC.

Bibliographic Details

Justin Iveland; Marco Piccardo; Nathan Young; Shuji Nakamura; James S. Speck; Claude Weisbuch; Lucio Martinelli; Jacques Peretti; Joo Won Choi

AIP Publishing

Physics and Astronomy

Provide Feedback

Have ideas for a new metric? Would you like to see something else here?Let us know