Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: A Novel Method to Fabricate Silicon Nanowire p–n Junctions by a Combination of Ion Implantation and in-situ Doping | Nanoscale Res Lett 2010 5 243-246 DOI s11671-009-9472-x NANO EXPRESS A Novel Method to Fabricate Silicon Nanowire p-n Junctions by a Combination of Ion Implantation and in-situ Doping Pratyush Das Kanungo Reinhard Kogler Peter Werner Ulrich Gosele Wolfgang Skorupa Received 9 October 2009 Accepted 14 October 2009 Published online 8 November 2009 to the authors 2009 Abstract We demonstrate a novel method to fabricate an axial p-n junction inside 111 oriented short vertical silicon nanowires grown by molecular beam epitaxy by combining ion implantation with in-situ doping. The lower halves of the nanowires were doped in-situ with boron concentration 1018 cm-3 while the upper halves were doubly implanted with phosphorus to yield a uniform concentration of 2 X 1019 cm-3. Electrical measurements of individually contacted nanowires showed excellent diode characteristics and ideality factors close to 2. We think that this value of ideality factors arises out of a high rate of carrier recombination through surface states in the native oxide covering the nanowires. Keywords Nanowire p-n Junction Ion implantation In-situ doping Electrical properties Introduction In order to make use of silicon nanowires Si NWs 1 in nano-devices selective doping to form p-n junctions or p and n wells is a necessity. Till date a host of devices with selectively doped Si NWs have been demonstrated 1 2 . Out of them axial p-n 3 and p-n-i 4 junction in Si NWs have shown the potential to be used as solar cells . However axial p-n junctions in NWs grown by the vapor- P. D. Kanungo El P. Werner U. Gosele Max Planck Institute of Microstructure Physics Weinberg 2 06120 Halle Germany e-mail kanungo@ R. Kogler W. Skorupa Forschungszentrum Dresden Rossendorf FWIM 01314 Dresden Germany liquid-solid VLS technique have mostly been fabricated by purely in-situ doping 3 5 6 . It has been observed that a pure in-situ doping to fabricate an axial junction may result in unwanted lateral doping
