Research on photoelectric characteristics of (S, Se) co-doped silicon fabricated by femtosecond-laser irradiation

摘要

AbstractMicro-structured (S, Se) co-doped and Se-doped silicon are prepared via femtosecond laser irradiating Si coated with Si-Se bilayer films in the presence of SF6and N2. The S-doped silicon is prepared by irradiating crystalline silicon surface via femtosecond laser in atmosphere of SF6. The samples are made with the same thickness of Se film and the same gas pressure of SF6or N2. The surface morphology, optical and electronic properties of S-doped, Se-doped and (S, Se) co-doped silicon are studied systematically, which show that co-doping is beneficial to improve the doping concentration and photoresponse of doped silicon. The n+–n photodiodes are fabricated from the three doped silicon annealed at 775 K for 1 h and (S, Se) co-doped silicon photodiode are fabricated for the first time. At 1064 nm, the responsivity achieves 1.60 A/W at −12 V reverse bias for the (S, Se) co-doped silicon photodiode, which is higher than that of S or Se doped silicon photodiode. This investigation demonstrates that (S, Se) co-doping has potential to improve the property of black silicon and facilitate its application in optoelectronic devices.