Modulation response of quantum dot nano-LEDs and nano-lasers

In this paper, the authors present calculations of the modulation bandwidth of quantum dot nano-LEDs based on a detailed model for the spontaneous emission. The model includes details about the optical and electronic density-of-states (DOS) and predicts that the Purcell enhancement will be partially cancelled if the electronic DOS is much broader than the optical DOS as is the case for quantum well devices [3]. Quantum dot structures potentially have much narrower electronic DOS, but are subject to size fluctuations leading to inhomogeneous broadening, that offsets the Purcell enhancement.