OPTICAL PROPERTIES OF STRAINED INP QUANTUM DOTS IN GA0.5IN0.5P STUDIED BY SPACE-CHARGE TECHNIQUES

摘要

In this paper, we report on the optical properties of coherently grown InP quantum dots embedded in Ga0.5In0.5P. Using photocurrent and photocapacitance techniques, we independently obtain an onset of 1.635 eV at 76 K for absorption in the dots. The spectral distribution of the current and capacitance signals displays two steps of similar height. We interpret these steps as the convoluted absorption spectrum of an ensemble of dots with asymmetric confinement of charge carriers. In addition, from photocurrent spectra obtained at different temperatures, we have estimated the temperature dependence of the mean effective band gap of the dots. [References: 16]