Electroluminescence from the sidewall quantum wells in the V-shaped pits of InGaN light emitting diodes

Abstract

InGaN/GaN multi-quantum well (MQW) light emitting diodes with heavily Mg doped and unintentionally doped (UID) low-temperature Al0.2Ga0.8N electron blocking layer (EBL) were investigated. Broad short-wavelength electroluminescence peak, which has strong relative intensity to the main emission, was found in the UID-EBL sample at cryogenic temperatures. Study suggests that the broad peak is emitted by the sidewall MQWs. This result indicates that the electroluminescence of sidewall MQWs, in which the carrier density is high enough, can be detected at cryogenic temperatures. The lineshape variation with current density reveals detailed information on the process of carrier injection into the sidewall MQWs.

Efficiency and Forward Voltage of Blue and Green Lateral LEDs with V-shape defects and Random Alloy Fluctuation in Quantum Wells

“…We use these parameters in the following discussion. The region between the vertical black dotted lines correspond to the TD along the direction {0001} with a 30 nm width at the center of the V-defect, and the V-defect sidewall QWs are inclined about 60 • according to both transmission electron microscopy (TEM) and scanning TEM, 32,33 which is consistent with early work showing that the sidewalls are 10 11 planes. In addition, the thickness of the c-plane QWs is 3 nm.…”

3D numerical modeling of the carrier transport and radiative efficiency for InGaN/GaN light emitting diodes with V-shaped pits

“…29 The middle orange line is the location of TDs that is assumed to be 20 nm width according to TEM and Scanning Transmission Electron Microscope (STEM). 15,30 …”

InGaN/GaN Structures: Effect of the Quantum Well Number on the Cathodoluminescent Properties

“…Recently, V‐pits have been found to have a positive effect on the InGaN PL properties . Several explanations were suggested, one of which is strain relaxation and reduction in QW region.…”