- About Us
- Career Center
- Nano-Social Network
- Nano Consulting
- My Account
December 20th, 2007
The high demand for efficient and inexpensive renewable energy sources is leading to increased research in organic photovoltaics. Among the different types of devices, dye-sensitized solar cells (DSSCs) based on porous titanium dioxide (TiO2) nanoparticle layers1 can achieve the highest efficiency, exceeding 10%. However, electron transport through a random TiO2 network is typically very slow.2 Improving its performance means developing novel organic dyes. Alternatively, replacing the TiO2 layer with one having a different nanostructure could also potentially achieve both improved charge transport and collection.
To this end, one could employ 1D nanostructures such as nanowires or nanotubes. Yet though 1D arrays enable simple pathways for electrons to reach electrodes, they also have smaller surface areas compared to random nanoparticle networks, thus leading to reduced performance. For example, the efficiency3 of 6.89% for an ∼20μm-long DSSC made of TiO2 nanotube arrays is still lower than that routinely achieved using a porous layer. Because increased surface areas can be obtained using longer nanotubes of smaller diameter, much effort has been invested in developing novel anodization procedures aimed at improving nanotube form and structure.3-6 Anodization conditions such as those determined by the type of electrolyte or the voltage applied, among others, measurably affect the morphology of the nanotubes (see Figure 1). However, the specific fabrication procedure employed also determines the crystal quality, as well as the defect types and densities, which in turn regulate charge transport.
|Related News Press|
News and information
Researchers develop new way to manufacture nanofibers May 21st, 2015
Cotton fibres instead of carbon nanotubes May 9th, 2015
Visualizing How Radiation Bombardment Boosts Superconductivity: Atomic-level flyovers show how impact sites of high-energy ions pin potentially disruptive vortices to keep high-current superconductivity flowing May 23rd, 2015
Efficiency record for black silicon solar cells jumps to 22.1 percent: Aalto University's researchers improved their previous record by over 3 absolute percents in cooperation with Universitat Politècnica de Catalunya May 18th, 2015