Microstructuring and doping of silicon with nanosecond laser pulses

We microstructure and dope silicon surfaces in SF6 atmosphere using nanosecond Nd:YAG laser pulses. The effects of scanning speed and laser pulse energy on surface morphology, optical and electronic properties of laser treated silicon are studied. When the scanning speed is 0.2 mm/s and the laser energy is 290 mJ, the absorptance of microstructured silicon can reach 90% in the visible spectrum and 80% in the infrared spectrum. In addition, its Hall mobility is measured as about 600 cm2 V−1 s−1. The electron diffraction shows that the irradiated silicon surface is crystalline and no disordered surface layer is found, which is good for optoelectronic applications.