Optical excitation dependent emission properties of InGaN quantum wells

Fully microscopic many-body calculations are used to study the carrier and polarization dynamics in optically excited InGaN quantum wells. For long-pulse or stationary (CW) optical excitation conditions, it is shown that the strong excitation-induced dephasing due to the excited charge carriers leads to an effective spectral width of the created polarization in the range of several hundred meV. The subsequent polarization to population conversion results in broad carrier distributions spreading over energy regions well above and below the central excitation energy. Without invoking Auger transitions, it is shown that this model can explain experiments observing ultraviolet quantum-well photoluminescence after resonant CW excitation of a neighboring green emitting quantum well Binder et al. (Appl. Phys. Lett. 103:071108, 2013).