Synergic effect of N and Se facilitates photoelectric performance of co-hyperdoped silicon

N and Se co-hyperdoped silicon (Si:N/Se) is prepared using deposited Se films on Si followed by femtosecond (fs)-laser irradiation in the atmosphere of NF3. The optical and crystallinity characteristics of the Si:N/Se are determined by the precursor Se film and laser fluence. The photodetector fabricated from the Si:N/Se shows remarkable responsivity of 24.8 and 19.8 A/W at the wavelength of 840 and 1060 nm, respectively, outperforming the photodetectors fabricated from Si:N, Si:S and Si:S/Se (the latter two are fabricated in SF6). The better photoelectric characteristics of Si:N/Se further facilitate the application of the co-hyperdoping method in optoelectronic devices.