Fig. 1. (a) SEM image of QDs used in the research. (b) Photoluminescence spectra of QDs (0.5 mg/mL) and original PSi sample at an excitation wavelength of 370 nm.

Fig. 2. Top-view and cross-sectional view SEM images of PSi sample.

Fig. 3. Red shift of multilayer PSi sample after the infiltration of QDs.

Fig. 4. Fluorescence intensity of the above PSi sample with or without QDs coupled.

Fig. 5. Reflectance spectra of two types of PSi devices after coupling with GOQDs’ (sample 1) high reflection band coinciding with the fluorescence emission spectra. In sample 2, the high reflection band was far beyond the fluorescence emission spectra of the GOQDs.

Fig. 6. Fluorescence emission spectrum of the infiltrated PSi sample: fluorescence of the mutilayer sample (1), whose high reflectance band is located at fluorescence (black line), fluorescence of mutilayer sample (2), whose high reflectance was beyond the fluorescence emission spectra (red line), and the fluorescence of the single-layer sample (blue line).