Photocurrent spectra and specific detectivity. Of Ge/Si QD samples where the capping temperature Tcap was systematically varied. (a) Series of responsivity spectra measured at temperature of 90 K with no applied bias (Ub = 0 V). The spectra have been vertically displaced for clarity. (b) Detectivity as a function of applied bias. The measurement temperature is 90 K. For the samples with Tcap = 300°C, 500°C, and 600°C, the data were taken at λ = 3 μm. For the samples with Tcap = 700°C and 750°C, the peak detectivity is shown.
Yakimov et al. Nanoscale Research Letters 2012 7:494 doi:10.1186/1556-276X-7-494