The solar power received by Earth far exceeds global power demands. Despite this, infrastructure shortages and high capital costs prevent the wide-scale adoption of photovoltaics to displace conventional energy technologies relying on carbon-based fuels. In response, new concepts and materials have been explored to develop next-generation solar cells capable of operating more efficiently and cheaply. Over the past decade, single semiconductor nanowire (NW) and NW array devices have emerged as promising platforms with which to examine new concepts. Small distances in NWs allow for efficient charge separation while tunable photonic modes permit light absorption properties distinct from bulk materials. Furthermore, the synthesis and fabrication of NW devices presents new opportunities such as with incorporation of complex heterostructures or use of cheaper substrates. Here, we present a critical discussion of the benefits and remaining challenges related to utilization of NWs for solar energy conversion and emphasize the synthetic advances leading towards significant improvement in the electrical and optical performance of NW devices. We conclude by articulating the unique capabilities of solar cells assembled from multiple, distinct NWs. © 2014 IUPAC and De Gruyter Berlin Boston.

Thomas Kempa    Charles Lieber    

Pure and Applied Chemistry

2014

Over the past decade extensive studies of single semiconductor nanowire and nanowire array photovoltaic devices have explored the potential of these materials as platforms for a new generation of efficient and cost-effective solar cells. This feature review discusses strategies for implementation of semiconductor nanowires in solar energy applications, including advances in complex nanowire synthesis and characterization, fundamental insights from characterization of devices, utilization and control of the unique optical properties of nanowires, and new strategies for assembly and scaling of nanowires into diverse arrays that serve as a new paradigm for advanced solar cells. © 2013 The Royal Society of Chemistry.

Thomas Kempa    Day Robert    Kim Sun-Kyung    Hong gyu Park    Charles Lieber    

Energy and Environmental Science

2013

The interface between nanoscale electronic devices and biological systems enables interactions at length scales natural to biology, and thus should maximize communication between these two diverse yet complementary systems. Moreover, nanostructures and nano -structured substrates show enhanced coupling to artificial membranes, cells, and tissue. Such nano-bio interfaces offer better sensitivity and spatial resolution as compared to conventional planar structures. In this work, we will report the electrical properties of silicon nanowires (SiNWs) interfaced with embryonic chicken hearts and cultured cardiomyocytes. We developed a scheme that allowed us to manipulate the nanoelectronic to tissue/cell interfaces while monitoring their electrical activity. In addition, by utilizing the bottom-up approach, we extended our work to the subcellular regime, and interfaced cells with the smallest reported device ever and thus exceeded the spatial and temporal resolution limits of other electrical recording techniques. The exceptional synthetic control and flexible assembly of nanowires (NWs) provides powerful tools for fundamental studies and applications in life science, and opens up the potential of merging active transistors with cells such that the distinction between nonliving and living systems is blurred. © 2013 IUPAC.

Tzahi Cohen-Karni    Charles Lieber    

Pure and Applied Chemistry

2013

Semiconductor nanowires configured as the active channels of field-effect transistors (FETs) have been used as detectors for high-resolution electrical recording from single live cells, cell networks, tissues and organs. Extracellular measurements with substrate supported silicon nanowire (SiNW) FETs, which have projected active areas orders of magnitude smaller than conventional microfabricated multielectrode arrays (MEAs) and planar FETs, recorded action potential and field potential signals with high signal-to-noise ratio and temporal resolution from cultured neurons, cultured cardiomyocytes, acute brain slices and whole animal hearts. Measurements made with modulation-doped nanoscale active channel SiNW FETs demonstrate that signals recorded from cardiomyocytes are highly localized and have improved time resolution compared to larger planar detectors. In addition, several novel three-dimensional (3D) transistor probes, which were realized using advanced nanowire synthesis methods, have been implemented for intracellular recording. These novel probes include (i) flexible 3D kinked nanowire FETs, (ii) branched intracellular nanotube SiNW FETs, and (iii) active silicon nanotube FETs. Following phospholipid modification of the probes to mimic the cell membrane, the kinked nanowire, branched intracellular nanotube and active silicon nanotube FET probes recorded full-amplitude intracellular action potentials from spontaneously firing cardiomyocytes. Moreover, these probes demonstrated the capability of reversible, stable, and long-term intracellular recording, thus indicating the minimal invasiveness of the new nanoscale structures and suggesting biomimetic internalization via the phospholipid modification. Simultaneous, multi-site intracellular recording from both single cells and cell networks were also readily achieved by interfacing independently addressable nanoprobe devices with cells. Finally, electronic and biological systems have been seamlessly merged in 3D for the first time using macroporous nanoelectronic scaffolds that are analogous to synthetic tissue scaffold and the extracellular matrix in tissue. Free-standing 3D nanoelectronic scaffolds were cultured with neurons, cardiomyocytes and smooth muscle cells to yield electronically- innervated synthetic or 'cyborg' tissues. Measurements demonstrate that innervated tissues exhibit similar cell viability as with conventional tissue scaffolds, and importantly, demonstrate that the real-time response to drugs and pH changes can be mapped in 3D through the tissues. These results open up a new field of research, wherein nanoelectronics are merged with biological systems in 3D thereby providing broad opportunities, ranging from a nanoelectronic/ tissue platform for real-time pharmacological screening in 3D to implantable 'cyborg' tissues enabling closed-loop monitoring and treatment of diseases. Furthermore, the capability of high density scale-up of the above extra- and intracellular nanoscopic probes for action potential recording provide important tools for large-scale high spatio-temporal resolution electrical neural activity mapping in both 2D and 3D, which promises to have a profound impact on many research areas, including the mapping of activity within the brain. © 2013 Elsevier Ltd. All rights reserved.

Xiaojie Duan    Tianming Fu    Jia Liu    Charles Lieber    

Nano Today

2013

High spatiotemporal resolution interfaces between electrical sensors and biological systems, from single live cells to tissues, is crucial for many areas, including fundamental biophysical studies as well as medical monitoring and intervention. Herein, we summarize recent progress in the development and application of novel nanoscale devices for intracellular electrical recording of action potentials and the effort of merging electronic and biological systems seamlessly in three dimensions by using macroporous nanoelectronic scaffolds. The uniqueness of these nanoscale devices for minimally invasive, large-scale, high spatial resolution, and three-dimensional neural activity mapping are highlighted. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Xiaojie Duan    Charles Lieber    

Chemistry - An Asian Journal

2013

Nanowire-based field-effect transistors, including devices with planar and three-dimensional configurations, are being actively explored as detectors for extra- and intracellular recording due to their small size and high sensitivities. Here we report the synthesis, fabrication, and characterization of a new needle-shaped nanoprobe based on an active silicon nanotube transistor, ANTT, that enables high-resolution intracellular recording. In the ANTT probe, the source/drain contacts to the silicon nanotube are fabricated on one end, passivated from external solution, and then time-dependent changes in potential can be recorded from the opposite nanotube end via the solution filling the tube. Measurements of conductance versus water-gate potential in aqueous solution show that the ANTT probe is selectively gated by potential changes within the nanotube, thus demonstrating the basic operating principle of the ANTT device. Studies interfacing the ANTT probe with spontaneously beating cardiomyocytes yielded stable intracellular action potentials similar to those reported by other electrophysiological techniques. In addition, the straightforward fabrication of ANTT devices was exploited to prepare multiple ANTT structures at the end of single probes, which enabled multiplexed recording of intracellular action potentials from single cells and multiplexed arrays of single ANTT device probes. These studies open up unique opportunities for multisite recordings from individual cells through cellular networks. © 2012 American Chemical Society.

Ruixuan Gao    Strehle Steffen    Bozhi Tian    Tzahi Cohen-Karni    Ping Xie    Xiaojie Duan    Quan Qing    Charles Lieber    

Nano Letters

2012

Advances in nanoscience and nanotechnology critically depend on the development of nanostructures whose properties are controlled during synthesis. We focus on this critical concept using semiconductor nanowires, which provide the capability through design and rational synthesis to realize unprecedented structural and functional complexity in building blocks as a platform material. First, a brief review of the synthesis of complex modulated nanowires in which rational design and synthesis can be used to precisely control composition, structure, and, most recently, structural topology is discussed. Second, the unique functional characteristics emerging from our exquisite control of nanowire materials are illustrated using several selected examples from nanoelectronics and nano-enabled energy. Finally, the remarkable power of nanowire building blocks is further highlighted through their capability to create unprecedented, active electronic interfaces with biological systems. Recent work pushing the limits of both multiplexed extracellular recording at the single-cell level and the first examples of intracellular recording is described, as well as the prospects for truly blurring the distinction between nonliving nanoelectronic and living biological systems. Copyright © Materials Research Society 2011.

Charles Lieber    

MRS Bulletin

2011

Nanoscience offers the promise of producing revolutionary advances in many areas of science and technology, ranging from electronics and computing to biology and medicine, yet the realization of this promise will depend critically on the rational development of unique nanoscale structures whose properties and/or function are controlled during materials synthesis. This review will illustrate these concepts using nanowires as a platform material. First, a brief historical perspective on emergence of nanowires as a central material will be presented. Second, the 'chemical' synthesis, atomic-level structural characterization and properties of complex modulated nanowires will be discussed with an emphasis on structures with radial and axial dopant modulation, and novel but controlled structural modulations. The implementation of these functional nanowires as a platform for investigating fundamental properties and performance limits of nanoscale quantum electronic and photovoltaic devices at the single nanowire level will be described. Second, the development of active interfaces between nanowire nanoelectronic devices and biological systems will be discussed, including label-free electronic detection at the single molecule level and multiplexed recording from individual cells through complex biological tissue, such as the brain. In addition, the development of novel nanowire probes that exploit unique synthetic capabilities for the nanowire platform and move beyond capabilities of conventional electrophysiological techniques will be discussed. Last, a critical look at progress made and scientific challenges that remain to realize true technologies in the future will be reviewed. ©2010 IEEE.

Charles Lieber    

INEC 2010 - 2010 3rd International Nanoelectronics Conference, Proceedings

2010

GaN/AlN/AlGaN/GaN nanowire metal-insulator-semiconductor field-effect transistors (MISFETs) have been fabricated for the first time with submicrometer gate lengths. Their microwave performances were investigated. An intrinsic current-gain cutoff frequency F of 5 GHz as well as an intrinsic maximum available gain F cutoff frequency of 12 GHz have been obtained for the first time and associated with a gate length of 0.5 μ. These results show the great potentiality of GaN-based nanowire FETs for microwave applications. © 2009 IEEE.

Vandenbrouck Simon    Madjour Kamel    Theron Didier    Yajie Dong    Yat Li    Charles Lieber     Ducatteau Gaquière   

IEEE Electron Device Letters

2009

Mamidala jagadesh Kumar    Reed Mark A.    Amaratunga G.    Cohen    David Janes    Charles Lieber     Meyya Meyyappan.    Lars erik Wernersson    Kanglong Wang    Robert Chau    Theodore ted Kamins    Mark Lundstrom    郁彬    Chongwu Zhou   

IEEE Transactions on Electron Devices

2008