Electrical Characterization of InAs/InP Self-Assembled Quantum Dots by Deep-Level Transient Spectroscopy

We have investigated the confined energy level of InAs quantum dots embedded in InP layer using deep-level transient spectroscopy (DLTS) measurement. The higher temperature for the capping layer growth yields a low activation energy (Ea=0.56 eV) and a low barrier height (EeB=0.18 eV) whereas the lower temperature yields a high activation energy (Ea=0.82 eV) and high barrier height (EeB=0.52 eV). It was found that the higher temperature for the growth of the capping layer provides a condition for enhancing the confinement energy in InAs QDs/InP structure.