Massive transfer of vertically aligned Si nanowire array onto alien substrates and their characteristics

• Published in: Applied surface science Vol. 255; no. 20; pp. 8566 - 8570
• Main Authors: Shiu, Shu-Chia, Hung, Shih-Che, Chao, Jiun-Jie, Lin, Ching-Fuh
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 30.07.2009; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Optical absorption; Physics; Silicon nanowire; Transfer; X-ray diffraction; Transfer; X-ray diffraction; Silicon nanowire; Optical absorption; Silicon; XRD; Nanowires; Arrays; Nanostructured materials
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2009.06.021

Si nanowires (NWs) are promising materials for future electronic, photovoltaic, and sensor applications. So far the Si NWs are mainly formed on particular substrates or at high temperatures, greatly limiting their application flexibility. Here we report a low temperature process for forming and massively transferring vertically aligned Si NWs on alien substrates with a large density of about (3–5) × 10 7 NWs/mm 2. The X-ray diffraction spectrum reveals that the transferred NWs exhibit almost the same crystal property as the bulk Si. Our investigation further shows that the transferred NWs have exceptional optical characteristics. The transferred Si NWs of 12.14 μm exhibit the transmittance as low as 0.3% in the near infrared region and 0.07% in the visible region. The extracted absorption coefficient of Si NWs in the near infrared region is about 3 × 10 3 cm −1, over 30 times larger than that of the bulk Si. Because of the low temperature process, it enables a large variety of alien substrates such as glass and plastics to be used. In addition, the exceptional properties of the transferred NWs offer potential applications for photovoltaic, photo-detectors, sensors, and flexible electronics.