Ae. Yunovich et Ve. Kudryashov, Energy diagram and recombination mechanisms in InGaN/AlGaN/GaN heterostructures with quantum wells, PHYS ST S-B, 228(1), 2001, pp. 141-145
Electroluminescence spectra of GaN based LEDs are analyzed quantitatively u
sing a model of 2D density of states with band tails. Calculations take int
o account an energy diagram with given band offsets between AlGaN, InGaN an
d GaN layers. The model describes spectral shapes with four fitting paramet
ers in a wide range of currents and intensities with a good accuracy. Fluct
uations of well thickness (heterointerface roughness), of In content, of ch
arged impurities and piezoelectric fields are discussed for an evaluation o
f the exponential tail parameter of 2D density of states in the active regi
on. Spectral maxima move with current changes due to the filling of the ban
d tails and redistribution of current carriers between regions with a large
r probability of radiative recombination. 2D concentrations and lifetimes o
f minority carriers in active layers are evaluated from the parameters of t
he model.