Sensitivity of indium molar fraction in InGaN quantum wells for near-UV light-emitting diodes
Abstract
InGaN-based quantum wells (QWs) have higher threading dislocation density (TDD) in InGaN
Light-emitting diode (LED). Despite of higher TDD, variation of Indium (In) molar fraction in the
QW generate localized excitons with higher Indium composition, thus preventing bound carriers
from non-radiative recombination. In this work, the sensitivity of the Indium molar fraction in
InGaN QWs is explored for near-ultraviolet (UV) LEDs. The theoretically calculated results show
that as the Indium composition increases in InGaN QWs, the radiative recombination increases
along with an increase in carrier injection efficiency. The reduced non-radiative recombination
for higher Indium composition leads to the enhanced spontaneous emission rate and internal
quantum efficiency (IQE). For lowered Indium composition, the peak emission wavelength of the
InGaN LEDs shift toward the shorter wavelength and the performances degrade drastically. Hence
for shorter UV LEDs, the AlGaN-based device structure should be a suitable choice.