Fig. 1. Curve of silicon absorption coefficient and surface reflectance with wavelength

Fig. 2. UV enhanced Si APD device structure

Fig. 3. Ultraviolet enhanced Si APD, (a) electric field distribution; (b) IV curve and multiplication curve

Fig. 4. Curve of the refractive index dependence on wavelength of silicon

Fig. 5. Photocurrent spectra of Si APD under different conditions in shortwave antireflection films

Fig. 6. Broadband Si APD device structure

Fig. 7. Broadband Si APD, (a) electric field; (b) impurity concentration profile

Fig. 8. IV and multiplication curves of Si APD simulated by the above structure under 905 nm illumination

Fig. 9. The Spectrum of Si APD，（a） without antireflection coating； （b） with antireflection coating

Fig. 10. Broadband Si APD photocurrent spectrum under different voltages