Figure 2
Photoluminescence in the visible detection range.
(a) Typical PL spectra obtained under 2.33 eV continuous wave excitation for ~110 nm octahedral (black) and irregular (red) Si NP’s in the range 1.3–1.7 eV for two different laser excitation powers. (b) Power dependence of intensity of the two samples under 2.33 eV continuous wave excitation depicted in double logarithmic representation. The integrated PL intensity is determined by integrating the PL spectra – Fig. 2(a) – between 1.4 and 1.5 eV. The power dependences of both samples, depicted in double logarithmic representation, show a superlinear behavior with a slope up to ~10 and a four order of magnitude enhancement in the investigated power range.
