I have made a bottom contact pentacene thin film transistor and deposited gold nanoparticles with different spacing and different channel length. What is the contact between gold nanoparticles and pentacene and what type of tunneling barrier will form (energy band diagram)?
Qualitatively, you may want to look out for spectroscopic work (photoelectron spectrscopy, inverse photoelectron spectroscopy, NEXAFS and optical, if available) for pentacene adsorbed on Au (or Ag) surfaces. At the detailed level, the distribution in size and shape of your nanoparticles and that of the detailed arrangements of NPs and molecules will lead to a statistical distribution of states which define the contact behavior of the NPs. So I'd tend to say that there's no universal band diagram but you can work out an approximate one from surface work.
You may have to consider a Coulomb barrier, though, when considering transport. (It costs Coulomb energy to charge a NP. The smaller the NP the higher the energy cost. Watch out for 'coulomb blockade' in the literature). You can also check whether there is some tunneling spectroscopy work (done with an STM, preferably at low temperature) for systems similar to yours in the literature.
Thank you very much Dr Kai Fauth,but here I want to know the Tunneling effect.In the tunneling, different kinds of barriers are forming,in which exactly what kind of barrier should be forming.If you have any links regarding that please attache here
In general, there are two possible injection mechanisms for the interface of metal/organic layer, i.e., Schottky thermionic emission and tunneling. In my study i found from the temperature dependence of ID-VD curves in pentacene based transistors with gold electrode, that the charge injection characteristics can be fitted by the Schottky emission mechanism. check the below link . u can aslo check my publications . my all research based on that work..
http://apl.aip.org/resource/1/applab/v102/i6/p061105_s1?isAuthorized=no
if u need any PDF file of my publication plz make request on the publication
https://www.researchgate.net/publication/23985790_Control_of_single-electron_charging_of_metallic_nanoparticles_onto_amorphous_silicon_surface?ev=prf_pub
Article Control of Single-Electron Charging of Metallic Nanoparticle...
Normally you would get a hole injection barrier, but this will depend on a lot of details. The alignment between the various energy levels cannot normally be predicted with any certainty, as this depends on the kind of interactions between the molecules and the nanoparticles. In addition, tunneling exchange may only take place for each individual charge transfer step, and the longer range transport may be controlled by a different mechanism. You need some temperature-dependent i-V curves at the least here...
Thank you very much sir for your good answer,If you do not mine please send me that article in PDF format, here It is subscribed
In addition to my answer. I suppose, that the important difference between Au and Ag nanoparticles - the existence of oxide layer on the surface of Ag NP and the absence of such layer on the Au NP surface. Early, we obtained similar results with Au and Ag nanocomposites, based on different cellulose derivatives.
Sorry, Ajaya. I can't find your e-mail to send you the article. Send it to me, please.
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology
- Nanostructures
- Thin Films