Enhanced injection efficiency and light output in bottom tunnel-junction light-emitting diodes

Tunnel-injection GaN quantum dot ultraviolet light-emitting diodes

We demonstrate a GaN quantum dot ultraviolet light-emitting diode that uses tunnel injection of carriers through AlN barriers into the active region. The quantum dot heterostructure is grown by molecular beam epitaxy on AlN templates. The large lattice mismatch between GaN and AlN favors the formation of GaN quantum dots in the Stranski-Krastanov growth mode. Carrier injection by tunneling can ...

Contact Injection into Polymer Light-Emitting Diodes

The variation of current I with voltage V for poly(phenylene vinylene) and other polymer light-emitting diodes has been attributed to carriers tunneling into broad conduction and valence bands. In actuality the electrons and holes tunnel into polaron levels and transport is by hopping among these levels. We show that for small injection the I-V characteristic is determined mainly by the image f...

Current injection efficiency induced efficiency-droop in InGaN quantum well light-emitting diodes

Current injection efficiency and its impact on efficiency-droop in InGaN single quantum well (QW) based light-emitting diodes (LEDs) are investigated. The analysis is based on current continuity relation for drift and diffusion carrier transport across the QW-barrier system. A self-consistent 6-band k p method is used to calculate the band structure for InGaN QW. The analysis indicates that the...

III–Nitride-Based Microarray Light-Emitting Diodes with Enhanced Light Extraction Efficiency

In this paper, the enhancement of light extraction efficiency in III–nitride-based light-emitting diodes (LEDs) with an array of microstructures is demonstrated numerically and experimentally at the near-ultraviolet (n-UV) spectral region. Two different microstructures are adopted to study the mechanism, including the shallow etching of microstructures on the indium–tin-oxide (ITO) p-contact an...

Junction temperature, spectral shift, and efficiency in GaInN-based blue and green light emitting diodes