Laser-induced greenish-blue photoluminescence of mesoporous silicon nanowires.

ABSTRACT: Solid silicon nanowires and their luminescent properties have been widely studied, but lesser is known about the optical properties of mesoporous silicon nanowires (mp-SiNWs). In this work, we present a facile method to generate greenish-blue photoluminescence (GB-PL) by fast scanning a focused green laser beam (wavelength of 532?nm) on a close-packed array of mp-SiNWs to carry out photo-induced chemical modification. The threshold of laser power is 5?mW to excite the GB-PL, whose intensity increases with laser power in the range of 5-105?mW. The quenching of GB-PL comes to occur beyond 105?mW. The in-vacuum annealing effectively excites the GB-PL in the pristine mp-SiNWs and enhances the GB-PL of the laser-modified mp-SiNWs. A complex model of the laser-induced surface modification is proposed to account for the laser-power and post-annealing effect. Moreover, the fast scanning of focused laser beam enables us to locally tailor mp-SiNWs en route to a wide variety of micropatterns with different optical functionality, and we demonstrate the feasibility in the application of creating hidden images.

SUBMITTER: Choi YR 

PROVIDER: S-EPMC4018655 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature