Dimensionality of photoluminescence spectrum of GaAs/AlGaAs system

We have theoretically studied the radiative recombination process between a conduction-band electron and a valence-band hole to analyze the photoluminescence (PL) spectrum. It is shown that due to the characteristics of the energy density of states, the line shape of the PL peak depends strongly on the dimensionality of the system under investigation, thus indicating the importance of the PL line shape in the identification of the corresponding optical transition process. Increasing the quantum confinement of a system from three-dimensional (3D bulk material) to two-dimensional (quantum well), one-dimensional (quantum wire) and zero-dimensional (quantum dot) results in a transition from a highly nonsymmetric PL peak to a symmetric Lorentzian one centered at the optical transition energy.