The effect of trimethylgallium flows in the AlInGaN barrier on optoelectronic characteristics of near ultraviolet light-emitting diodes grown by atmospheric pressure metalorganic vapor phase epitaxy

Abstract

The letter reports a theoretical and experimental study on the device performance of near ultraviolet light-emitting diodes ͑LEDs͒ with quaternary AlInGaN quantum barrier ͑QB͒. The indium mole fraction of AlInGaN QB could be enhanced as we increased the trimethylgallium flow rate. It was found the AlInGaN/InGaN LEDs can reduce forward voltage and improve light output power, compared with conventional GaN QB. By using advanced device simulation, it should be attributed to a reduction in lattice mismatch induced polarization mismatch in the active layer, which results in the suppression of electron overflow.

Enhanced Radiative Recombination Rate by Local Potential Fluctuation in InGaN/AlGaN Near-Ultraviolet Light-Emitting Diodes

“…The indium compositions of the quantum wells (QWs) in NUV LEDs are typically a few percent for wavelengths below 400 nm, which has a detrimental effect on light extraction efficiency (LEE) owing to the absorption of NUV light by the p-GaN layer [11]. The band-offset between the well and the barrier [2,3,12] is also affected. Thus, carriers overflow owing to the reduced carrier confinement in QWs, causing poor radiative recombination rates.…”

The Effect of Trimethylaluminum Flow Rate on the Structure and Optical Properties of AlInGaN Quaternary Epilayers

“…Recently, Yu et al [12] reported the optical and electrical properties of AlInGaN with various trimethylindium (TMIn) molar rates. Fu et al [13] reported the effect of trimethylgallium (TMGa) flow rate on the optoelectrical characteristics of AlInGaN. However, there are few reports available about AlInGaN structure and optical properties with varied trimethylaluminum (TMA) flow rate.…”

“…Fu et al [13] reported the effect of trimethylgallium (TMGa) flow rate on the optoelectrical characteristics of AlInGaN. However, there are few reports available about AlInGaN structure and optical properties with varied trimethylaluminum (TMA) flow rate.…”

Blue InGaN Light-Emitting Diodes With Multiple GaN-InGaN Barriers

“…Subsequently, various approaches toward the improvement of optical performance have been proposed. InGaN and AlGaInN barriers were proposed to reduce the lattice mismatch in active region, which results in suppression of electron overflow [3], [11]. LEDs with p-doped or n-doped barriers were recommended owing to the advantages of low turn-on voltage, low parasitic series resistance, or reduced p-n junction temperature [12], [13].…”