The current issue of Nanoscience and Nanotechnology - Asia is dedicated to the growth and applications of semiconductor nanowires. Nanowires are “one-dimensional” rods that have a diameter typically constrained to tens of nanometers or less and lengths much greater than the diameter (typically on the order of microns). Semiconductor nanowires are currently one of the leading topics in nanoscience and nanotechnology due to their vast applications in field effect transistors, photovoltaics, photodetectors and sensors, among other applications.
The present issue covers a wide range of Group IV, III-V and II-VI materials including Si, GaN, CdS, and ZnO nanowires. The most common mechanism of growing nanowires is the vapour-liquid-solid mechanism, whereby a metal seed particle acts as a collector for material in a physical or chemical vapour deposition process such as molecular beam epitaxy or metal organic chemical vapour deposition; although, as you will see in this issue, there are many other nanowire growth methods available.
Due to their large surface-to-volume ratio, nanowires can provide superior electrostatic properties in field effect transistors. In the article “Poly-Si Nanowire Device Technology”, Horng-Chih Lin provides a review of the progress made in poly-Si nanowire (NW) transistor technology in recent years and integration with modern poly-Si TFT-based electronics or CMOS circuitry.
Light trapping and waveguiding effects in nanowires can provide superior anti-reflection and light absorption properties, while enhancing carrier collection in photovoltaic and photodetector applications. One of the key issues in realizing these devices is the control of doping in nanowires. The contribution by Tengfei Xue et al. provides a review of ZnO nanowires with an emphasis on impurity doping control for photovoltaic devices. The paper by Mohammad Abbas Mahmood and Joydeep Dutta presents methods for controlling the growth of ZnO nanowires in a hydrothermal process.
The large surface area of nanowires makes them ideal candidates for next generation sensors where the conductivity of nanowires is modulated by their surface condition. The original research paper by Rui-Qin Zhang et al. presents novel theoretical work on the control of Si nanowire conductivity by surface passivation.
The paper by Shancheng Yan and Zhongdang Xiao provides a concise review of CdS nanowires for various optoelectronic applications in the visible range of the electromagnetic spectrum such as nonlinear optical devices, LEDs and solar cells.
Finally, two review articles in this issue are devoted to the topic of GaN nanowires. The paper by Prasana Sahoo et al. discusses the growth kinetics of GaN nanowires, while the article by Saeed Fathololoumi et al. presents InGaN nanowire heterostructures and optoelectronic device applications. The growth of InN nanowires, a topic of growing interest, is also presented in the latter article.