Increased Photoconductivity Lifetime in GaAs Nanowires by Controlled n-Type and p-Type Doping

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• 作者：Jessica L. Boland ; Alberto Casadei ; Gözde Tütüncüoglu ; Federico Matteini ; Christopher L. Davies ; Fauzia Jabeen ; Hannah J. Joyce ; Laura M. Herz ; Anna Fontcuberta i Morral ; Michael B. Johnston
• 刊名：ACS Nano
• 出版年：2016
• 出版时间：April 26, 2016
• 年：2016
• 卷：10
• 期：4
• 页码：4219-4227
• 全文大小：452K
• 年卷期：0
• ISSN：1936-086X

文摘

Controlled doping of GaAs nanowires is crucial for the development of nanowire-based electronic and optoelectronic devices. Here, we present a noncontact method based on time-resolved terahertz photoconductivity for assessing n- and p-type doping efficiency in nanowires. Using this technique, we measure extrinsic electron and hole concentrations in excess of 10¹⁸ cm^–3 for GaAs nanowires with n-type and p-type doped shells. Furthermore, we show that controlled doping can significantly increase the photoconductivity lifetime of GaAs nanowires by over an order of magnitude: from 0.13 ns in undoped nanowires to 3.8 and 2.5 ns in n-doped and p-doped nanowires, respectively. Thus, controlled doping can be used to reduce the effects of parasitic surface recombination in optoelectronic nanowire devices, which is promising for nanowire devices, such as solar cells and nanowire lasers.