Fabrication and Photovoltaic Characteristics of Coaxial Silicon Nanowire Solar Cells Prepared by Wet Chemical Etching

Nanostructured solar cells with coaxial p-n junction structures have strong potential to enhance the performances of the silicon-based solar cells. This study demonstrates a radial junction silicon nanowire (RJSNW) solar cell that was fabricated simply and at low cost using wet chemical etching. Experimental results reveal that the reflectance of the silicon nanowires (SNWs) declines as their length increases. The excellent light trapping was mainly associated with high aspect ratio of the SNW arrays. A conversion efficiency of ∼7.1% and an external quantum efficiency of ∼64.6% at 700 nm were demonstrated. Control of etching time and diffusion conditions holds great promise for the development of future RJSNW solar cells. Improving the electrode/RJSNW contact will promote the collection of carries in coaxial core-shell SNW array solar cells

Physical and Electrical Characteristics of Carbon Nanotube Network Field-Effect Transistors Synthesized by Alcohol Catalytic Chemical Vapor Deposition

Carbon nanotubes (CNTs) have been explored in nanoelectronics to realize desirable device performances. Thus, carbon nanotube network field-effect transistors (CNTNFETs) have been developed directly by means of alcohol catalytic chemical vapor deposition (ACCVD) method using Co-Mo catalysts in this work. Various treated temperatures, growth time, and Co/Mo catalysts were employed to explore various surface morphologies of carbon nanotube networks (CNTNs) formed on the SiO2/n-type Si(100) stacked substrate. Experimental results show that most semiconducting single-walled carbon nanotube networks with 5–7 nm in diameter and low disorder-induced mode (D-band) were grown. A bipolar property of CNTNFETs synthesized by ACCVD and using HfO2 as top-gate dielectric was demonstrated. Various electrical characteristics, including drain current versus drain voltage (Id-Vd), drain current versus gate voltage (Id-Vg), mobility, subthreshold slope (SS), and transconductance (Gm), were obtained

p-Cu2O-shell/n-TiO2-nanowire-core heterostucture photodiodes

This study reports the deposition of cuprous oxide [Cu2O] onto titanium dioxide [TiO2] nanowires [NWs] prepared on TiO2/glass templates. The average length and average diameter of these thermally oxidized and evaporated TiO2 NWs are 0.1 to 0.4 μm and 30 to 100 nm, respectively. The deposited Cu2O fills gaps between the TiO2 NWs with good step coverage to form nanoshells surrounding the TiO2 cores. The p-Cu2O/n-TiO2 NW heterostructure exhibits a rectifying behavior with a sharp turn-on at approximately 0.9 V. Furthermore, the fabricated p-Cu2O-shell/n-TiO2-nanowire-core photodiodes exhibit reasonably large photocurrent-to-dark-current contrast ratios and fast responses

A Novel Technology to Reduce the Antenna Charging Effects During Polysilicon Gate Electron-Cyclotron - IEEE Electron Device Letters

Abstract-A novel technique, which uses C12/02 mixed gas in the electron cyclotron resonance (ECR) etching system, has been proposed to remove the antenna charging effect of the MOS capacitors with 5-nm-thick oxides during polysilicon gate etching. The C12/02 can cause the trenching effect and prevents the gate oxide from the charging damage. Furthermore, the ECR system can provide high polysilicodoxide selectivity so that the Si substrate under gate oxide is not directly bombarded by the ions. Consequently, the E b d degradation of the MOS capacitors disappears as the trenching effect is apparent by using moderate C12/02 mixed gas

p-Cu₂O-shell/n-TiO₂-nanowire-core heterostucture photodiodes

<p>Abstract</p> <p>This study reports the deposition of cuprous oxide [Cu₂O] onto titanium dioxide [TiO₂] nanowires [NWs] prepared on TiO₂/glass templates. The average length and average diameter of these thermally oxidized and evaporated TiO₂NWs are 0.1 to 0.4 &#956;m and 30 to 100 nm, respectively. The deposited Cu₂O fills gaps between the TiO₂NWs with good step coverage to form nanoshells surrounding the TiO₂cores. The p-Cu₂O/n-TiO₂NW heterostructure exhibits a rectifying behavior with a sharp turn-on at approximately 0.9 V. Furthermore, the fabricated p-Cu₂O-shell/n-TiO₂-nanowire-core photodiodes exhibit reasonably large photocurrent-to-dark-current contrast ratios and fast responses.</p