Fig. 1. Atomic configurations for (a) undoped crystal Si (Si₆₄), (b) substitutional Ti-doped Si (Ti_SiSi₆₃), and (c) interstitial Ti-doped Si (Ti_iSi₆₄). The graphs below are the band structures for (d) Si₆₄, (e) relaxed Ti_SiSi₆₃, and (f) relaxed Ti_iSi₆₄ compounds.

Fig. 2. Optical absorption coefficients for the Si₆₄, Ti_SiSi₆₃, and Ti_iSi₆₄ compounds.

Fig. 3. (a) Absorptance spectra for the b-Si:Ti samples at different fluences and following RTA treatment at a temperature of 600°C. (b) Absorptance spectra for the b-Si:Ti samples (1.2 kJ/m²) before and after annealing under different temperatures, in which 25°C represents the unannealed sample of b-Si:Ti. The inset in (b) provides the variation in absorption at 1550 nm as a function of temperature.

Fig. 4. The obtained SEM images of the b-Si:Ti surface for different laser fluences at a rotation angle of 45° fabricated. (a) 1.2, (b) 2.5, (c) 4.5, and (d) 6.8 kJ/m², whereas their corresponding high magnification images are presented in (e)–(h).

Fig. 5. (a) Raman spectra for the b-Si:Ti samples manufactured under different laser fluences and compared with Si substrate; (b) Raman spectra for the b-Si:Ti samples (1.2 kJ/m²) before annealing and after RTA treatment under different temperatures, in which 25°C represents an unannealed b-Si:Ti sample.