Showing papers by "Sheng Xu published in 2011"
TL;DR: A comprehensive overview of the progress that has been made within the context of 1D ZnO nanostructures synthesized via wet chemical methods can be found in this paper, where the synthetic methodologies and corresponding growth mechanisms, different structures, doping and alloying, position-controlled growth on substrates, and finally, their functional properties as catalysts, hydrophobic surfaces, sensors, and in nanoelectronic, optical, optoelectronics, and energy harvesting devices.
Abstract: One-dimensional (1D) ZnO nanostructures have been studied intensively and extensively over the last decade not only for their remarkable chemical and physical properties, but also for their current and future diverse technological applications. This article gives a comprehensive overview of the progress that has been made within the context of 1D ZnO nanostructures synthesized via wet chemical methods. We will cover the synthetic methodologies and corresponding growth mechanisms, different structures, doping and alloying, position-controlled growth on substrates, and finally, their functional properties as catalysts, hydrophobic surfaces, sensors, and in nanoelectronic, optical, optoelectronic, and energy harvesting devices.
1,247 citations
TL;DR: This study exploited the noncentral symmetric nature of n-type ZnO nanowires/p-type GaN substrate to create a piezoelectric potential within the nanowire by applying stress and can be extended from ultraviolet range to visible range for a variety of optoelectronic devices.
Abstract: Light emission from semiconductors depends not only on the efficiency of carrier injection and recombination but also extraction efficiency. For ultraviolet emission from high band gap materials such as ZnO, nanowires have higher extraction efficiencies than thin films, but conventional approaches for creating a p–n diode result in low efficiency. We exploited the noncentral symmetric nature of n-type ZnO nanowire/p-type GaN substrate to create a piezoelectric potential within the nanowire by applying stress. Because of the polarization of ions in a crystal that has noncentral symmetry, a piezoelectric potential (piezopotential) is created in the crystal under stress. The piezopotential acts as a “gate” voltage to tune the charge transport and enhance carrier injection, which is called the piezo-phototronic effect. We propose that band modification traps free carriers at the interface region in a channel created by the local piezoelectric charges. The emission intensity and injection current at a fixed ap...
322 citations
TL;DR: In this article, the rational growth of ZnO and PZT nanowire arrays by seedless wet chemical methods is discussed, as well as the piezoelectric properties of PZr x Ti 1-x O 3 (PZT), which is an ideal material as actuator.
Abstract: As an outstanding member in the oxide nanowire family, ZnO nanowire is widely studied for its optical, semiconductive, and piezoelectric properties. PbZr x Ti 1-x O 3 (PZT), usually in the form of polycrystalline thin films, is known for its high piezoelectric coefficient and is an ideal material as actuator. In this review, we first briefly introduce the rational growth of ZnO and PZT nanowire arrays by seedless wet chemical methods. Utilizing the ordered ZnO nanowires grown on p-type substrates, we next present an array of single ZnO nanowire-based blue/near-UV light-emitting diodes (LEDs), including their fabrication process, electroluminescence (EL) spectra, and external quantum efficiency. Finally, we discuss the piezoelectric ZnO and PZT nanowire-enabled three-dimensionally integrated direct- and alternating-current nanogenerators, and their primary roles in self- powered nanosystems and for powering personal microelectronics.
6 citations
TL;DR: The critical technologies being developed include ZnO nanostructures with wide band gap for UV detection for a variety of threat warning applications as mentioned in this paper, and the experimental results on the structural, electrical and optical properties of ZNO nanowire for UV detectors.
Abstract: E-O Sensors are being developed for a variety of Military Systems Applications These include UV, Visible,
SWIR, MWIR and LWIR Nano Sensors In this paper, we will discuss growth and characterization of ZnO
Nanowires on a variety of substrates that include Silicon, ZnO and flexible substrates
The critical technologies being developed include ZnO nanostructures with wide band gap for UV detection
for a variety of threat warning applications We will present experimental results on the structural, electrical
and optical properties of ZnO nanowire for UV detectors Experimental results on ZnO based nanostructures
demonstrate enhanced UV sensitivity and path forward for larger arrays
1 citations
01 May 2011
TL;DR: In this paper, the authors demonstrate the piezoelectric effect on the responsivity of a metal-semiconductor-metal ZnO micro-/nanowire photodetector.
Abstract: We demonstrate the piezoelectric effect on the responsivity of a metal-semiconductor-metal ZnO micro-/nanowire photodetector. Piezo-phototronic effect can enhance the detection sensitivity more than fivefold for pW levels light detection.