Fig. 1. Schematic of dopant diffusion process during pulsed-laser melting and resolidification^[24]

Fig. 2. Selected area electron diffraction images of black silicon surface and current-voltage properties of junction^[20]. Selected area electron diffraction images of black silicon surface (a) before and (b) after annealing (975 K,30 min); (c) current-voltage properties of junction between laser-doped region and p-type substrate

Fig. 3. Photoelectric properties of black silicon photodetectors. (a) Photocurrent and dark current versus voltage for non-doped black silicon photodetector^[37]; (b) sub-band gap spectral responsivity as a function of photon energy for Ag-hyperdoped silicon-based photodetector. A kink with the threshold energy of 0.82 eV is obtained^[38]

Fig. 4. Device performance of sulfur-hyperdoped silicon-based photodetector prepared by femtosecond laser^[39]. (a) Responsivities for a black silicon photodetector under different bias voltages and comparison with commercial silicon and germanium photodetectors. The insets show the peak responsivity (left) and infrared responsivity (right) versus bias voltage; (b) photocurrent and dark current versus bias voltage for the black silicon photodetector

Fig. 5. Effect of nanosecond laser annealing on lattice structure^[48]. (a) Lattice structure of hyperdoped silicon with high crystallinity; (b) corresponding broad-spectral light absorptance

Fig. 6. Sulfur-nitrogen co-doped black silicon material. (a) Lattice structure of hyperdoped silicon co-doped with sulfur and nitrogen^[52]; (b) diagram and (c) photoresponsivity curve of photodetector based on co-doped black silicon^[54]

Fig. 7. Te-doped black silicon material and photodetector prepared at high temperature. (a) Lattice structure of single crystal black silicon hyperdoped with femtosecond laser at 700 K ^[55]; (b) comparison of responsivity of commercial detectors with single crystal black silicon detector

Fig. 8. Flexible single crystal silicon and flexible black silicon. (a) Bending performance of flexible and tailorable ultra-thin single crystal silicon^[62]; (b) light absorption of flexible black silicon fabricated by femtosecond laser irradiating SOI wafer before and after chemical etching^[67]

Fig. 9. High-performance sulfur-hyperdoped flexible silicon-based photodetector^[68]. (a) Diagram of flexible black silicon photodetector and surface morphology of the material; (b) photoresponsivity of flexible black silicon photodetector at various wavelengths for different bending radii