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.