Temperature Droop Characteristics of Internal Efficiency in <inline-formula> <tex-math notation="TeX">$\hbox{In}_{x}\hbox{Ga}_{1-x}\hbox{N/GaN}$</tex-math></inline-formula> Quantum Well Light-Emitting Diodes

Abstract

The temperature droop characteristics of internal efficiency (IE) in InGaN/GaN quantum well (QW) structures were investigated using the multiband effective mass theory. In the case of a relatively small Auger recombination (<; CA = 5 × 10-30 cm6s), the QW structure with a smaller In composition (x = 0.1) shows a larger hot/cold factor (IET1/IET2, with T1 > T2) than that with a larger In composition (x = 0.3) because the radiative recombination is dominant and the IE of the former is much larger than that of the latter. The hot/cold factors for QW structures with x = 0.1 and 0.3 are 0.85 and 0.71 at J = 100 A/cm2, respectively. On the other hand, in the case of a relatively large Auger recombination (> CA = 10-28 cm6s), the hot/cold factor (0.69) of the QW structure with a larger In composition is found to be larger than that (0.62) with a smaller In composition. This is attributed to the fact that the Auger recombination is dominant even for the QW structure with a small In composition and that the difference of the IE between two different temperatures decreases with increasing x.