Knut Deppert

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Photovoltaics based on nanowire arrays could reduce cost and materials consumption compared with planar devices but have exhibited low efficiency of light absorption and carrier collection. We fabricated a variety of millimeter-sized arrays of p-type/intrinsic/n-type (p-i-n) doped InP nanowires and found that the nanowire diameter and the length of the top(More)
Controlled growth of nanowires is an important, emerging research field with many applications in, for example, electronics, photonics, and life sciences. Nanowires of zinc blende crystal structure, grown in the <111>B direction, which is the favoured direction of growth, usually have a large number of twin-plane defects. Such defects limit the performance(More)
We report the temperature dependence of the Au-assisted growth of InAs nanowires in MOVPE. Extensive studies of the growth of such nanowires have attributed growth to the so-called vapor-liquid-solid (VLS) mechanism, with a liquid Au-In alloy particle. We assert here that growth is instead assisted by a solid particle and does not occur at all when the(More)
In this work we demonstrate experimentally the dependence of InSb crystal structure on the ratio of Sb to In atoms at the growth front. Epitaxial InSb wires are grown by a self-seeded particle assisted growth technique on several different III-V substrates. Detailed investigations of growth parameters and post-growth energy dispersive x-ray spectroscopy(More)
Semiconductor nanowires show promise for use in nanoelectronics, fundamental electron transport studies, quantum optics and biological sensing. Such applications require a high degree of nanowire growth control, right down to the atomic level. However, many binary semiconductor nanowires exhibit a high density of randomly distributed twin defects and(More)
The formation of nanostructures with controlled size and morphology has been the focus of intensive research in recent years. Such nanostructures are important in the development of nanoscale devices and in the exploitation of the properties of nanomaterials. Here we show how tree-like nanostructures ('nanotrees') can be formed in a highly controlled way.(More)
III-V-based nanowires usually exhibit random mixtures of wurtzite (WZ) and zinc blende (ZB) crystal structure, and pure crystal phase wires represent the exception rather than the rule. In this work, the effective group V hydride flow was the only growth parameter which was changed during MOVPE growth to promote transitions from WZ to ZB and from ZB to WZ.(More)
We demonstrate the growth of InSb-based nanowire heterostructures by metalorganic vapour phase epitaxy and use it to integrate InSb on extremely lattice-mismatched III-V nanowire templates made of InAs, InP, and GaAs. Influence of temperature, V/III ratio, and diameter are investigated in order to investigate the growth rate and morphology. The range of(More)
gold nanoparticles Jianing Chen, Weisheng Yang, Kimberly Dick, Knut Deppert, H. Q. Xu, Lars Samuelson, and Hongxing Xu Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603-146, Beijing 100080, People’s Republic of China School of Physics and Optoelectronics, Dalian University of(More)