دانلود رایگان ترجمه مقاله طراحی، سنتز و شاخصه بندی ساختارهای نانوسیم جدید برای فتوولتائیک‌ (نشریه degruyter 2011)

طراحی، سنتز و شاخصه بندی ساختارهای نانوسیم جدید برای فتوولتائیک‌ و پروب های درون سلولی

Design, synthesis, and characterization of novel nanowire structures for photovoltaics and intracellular probes

Abstract

Semiconductor nanowires (NWs) represent a unique system for exploring phenomena at the nanoscale and are expected to play a critical role in future electronic, optoelectronic, and miniaturized biomedical devices. Modulation of the composition and geo – metry of nanostructures during growth could encode information or function, and realize novel applications beyond the conventional lithographical limits. This review focuses on the fundamental science aspects of the bottom-up paradigm, which are synthesis and physical property characterization of semiconductor NWs and NW heterostructures, as well as proofof-concept device concept demonstrations, including solar energy conversion and intracellular probes. A new NW materials synthesis is discussed and, in particular, a new “nano – tectonic” approach is introduced that provides iterative control over the NW nucleation and growth for constructing 2D kinked NW superstructures. The use of radial and axial p-type/intrinsic/n-type (p-i-n) silicon NW (Si-NW) building blocks for solar cells and nanoscale power source applications is then discussed. The critical benefits of such structures and recent results are described and critically analyzed, together with some of the diverse challenges and opportunities in the near future. Finally, results are presented on several new directions, which have recently been exploited in interfacing biological systems with NW devices.

1 Introduction

Semiconductor nanowires (NWs) [1–8], nanocrystals [9–11], and carbon nanotubes [12–16] offer many opportunities for the assembly of nanoscale devices and arrays by the bottom-up paradigm [1–4]. Moreover, these nanomaterials demonstrate new and/or enhanced functions crucial to many areas of technology. Central to realizing applications through a bottom-up paradigm is the rational control of key nanomaterial parameters, including chemical composition, structure, size, morphology, and doping. It is these parameters that determine, for example, electronic and optoelectronic properties critical to predictable device function. Significantly, semiconductor NWs represent the nanomaterial system where these key parameters have been best controlled to date, have become a unique system for exploring phe-nomena at the nanoscale, and are also expected to play a critical role in future electronic and opto – electronic devices.

In this review, we first introduce a new “nanotectonic” approach that provides iterative control over the NW nucleation and growth for constructing 2D kinked NW superstructures [17]. Next, a rational, multistep approach toward the general synthesis of 3D branched NW heterostructures [18] is discussed, together with results on novel nanoscale electronic devices based on those new NW structures, e.g., self-labeled p-n diodes and field-effect transistors (FETs) in kinked NWs [17] and addressable light-emitting diode (LED) array and biological sensors in branched NWs [18].

Efforts toward using radial and axial p-type/intrinsic/n-type (p-i-n) silicon NW (Si-NW) building blocks for solar cells and nanoscale power source applications [19–22] include discussion of the critical benefits of such structures, description of recent results, and critical analysis and insights into diverse challenges and opportunities in the near future.

Finally, we present results on two new directions that have recently been exploited in interfacing biological systems with NW devices. It is first shown that Si-NW FET arrays fabricated on transparent substrates can be reliably interfaced to acute brain slices, and can be used to reveal spatially hetero – geneous functional connectivity in the olfactory cortex with high spatio-temporal resolutions [23]. Next, we demonstrate the first electrical recording of the intracellular potential with 3D nanoprobe devices [24]. Significantly, electrical recordings of spontaneously beating cardiomyocytes demonstrate that our 3D NW probes can continuously monitor the extra- to intracellular signals during cellular uptake [24]. The nanometer size, biomimetic surface coating, and flexible 3D device geometry make these active semiconductor nanoprobes new and powerful tools for intracellular measurements, and suggest future biomedical applications where the distinctions between living cells and electronic devices have been blurred [24].