Hyperdoped silicon (hSi) fabricated via femtosecond laser irradiation has emerged as a promising photoelectric material with strong broadband infrared (IR) absorption. In this work, we measured the optical absorptance of the hSi in the wavelength of 0.3–16.7 µm. Unlike the near to mid wavelength IR absorption, the mid-long wavelength IR (M–LWIR) absorption is heavily dependent on the surface morphology and the dopants. Furthermore, calculations based on coherent potential approximation (CPA) reveal the origin of free carrier absorption, which plays an important role in the M–LWIR absorption. As a result, a more comprehensive picture of the IR absorption mechanism is drawn for the optoelectronic applications of the hSi.

We investigate the angular distribution of high harmonic generation (HHG) from impulsively aligned CO2 molecules driving by the femtosecond laser. We first observe the HHG spectra under the different aligning angles and the different laser intensities. The angular distribution is found to be sensitive to both the harmonic order and the intensity of the driving laser pulse. At last, we theoretically and experimentally demonstrate the angular distribution with the different harmonic orders and the different laser intensities.

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.

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.