🚀 go-pugleaf

mihri@my-deja.com wrote:
> 
> Could anybody please advise on possible information sources, which give
> electron affinity of indium oxide (In2O3) and/or indium tin oxide?
> I was trying to search internet, but without much of success.
> Thanking in advance,
> Mihri.
> 
I doubt that anyone has measured it, unless these materials are of
significant interest to the surface scientists.  Measuring electron 
affinity requires a sophisticated high-vacuum photoemission apparatus.
And you only need this data if you are developing some sort of 
photocathode.

If, as I suspect is more likely, you are trying to infer a barrier
height for the oxide interface to some semiconductor or metal, 
do not believe the electron affinity rule for barrier hieghts, 
no matter how many times it has been repeated in the textbooks.  
It simply is not verified experimentally, unless the "electron 
affinity" is derived from the barrier height of the interface of
interest.  You need internal photoemission measurements of that 
interface to get a good estimate of the barrier height.

- Bill Frensley

William R. Frensley wrote:

> mihri@my-deja.com wrote:
> >
> > Could anybody please advise on possible information sources, which give
> > electron affinity of indium oxide (In2O3) and/or indium tin oxide?
> > I was trying to search internet, but without much of success.
> > Thanking in advance,
> > Mihri.
> >
> I doubt that anyone has measured it, unless these materials are of
> significant interest to the surface scientists.  Measuring electron
> affinity requires a sophisticated high-vacuum photoemission apparatus.
> And you only need this data if you are developing some sort of
> photocathode.
>
> If, as I suspect is more likely, you are trying to infer a barrier
> height for the oxide interface to some semiconductor or metal,
> do not believe the electron affinity rule for barrier hieghts,
> no matter how many times it has been repeated in the textbooks.
> It simply is not verified experimentally, unless the "electron
> affinity" is derived from the barrier height of the interface of
> interest.  You need internal photoemission measurements of that
> interface to get a good estimate of the barrier height.
>
> - Bill Frensley

Actually the above answer is not very precise. Electron affinity is a concept
that is accurate in the case of semiconductors. ITO is really used as a
transparent "metallic" contact. There are also plenty of cases where the
electron affinity has been measured in many ways. Take for example, diamond
(a semiconductor) which has a positive or negative electron affinity
depending on the surface orientation and the surface termination. The
electron affinity has been inferred using UPS, XPS, and kelvin probe. (see
for example the papers of Nemanich et al, Pate et al).
    I would look in the journals Applied Surface Science and Surface Science.
I would also check papers on InGaAs where somebody might have made
measurements on In rich InGaAs surfaces. JVST is also not a bad choice given
the technilogical relevance of the material. I would also do searches on
indium itself. It would not surprise me if somebody has made workfunction
measurements on bare and oxidized In surfaces.. For these kind of searches
you really need the services of some high power scientific database such as
INSPEC or ISI, which would be more than likely available at your local
university.

John Glesener

mihri@my-deja.com wrote:
: Could anybody please advise on possible information sources, which give
: electron affinity of indium oxide (In2O3) and/or indium tin oxide?
: I was trying to search internet, but without much of success.
: Thanking in advance,

If you can find it, first try V.I. Vedeneyev, L.V. Gurvich, V.N. 
Kondrat'yev, V.A. Medvedev, and Ye.L. Frankevich, _Bond Energies, 
Ionization Potentials and Electron Affinities_, New York:St. Martin's 
Press, 1966.  That has more affinities in once place than I've seen 
anywhere else.  The Soviets must have had some fondness for electron 
affinities, because it always seems like whenever I need an uncommon 
affinity, I find it in some Soviet lit.  Govoritje po russkji?
Then try Landolt and Boernstein, just because it's usually easy to find at 
the library.  If that fails, which it likely will, start digging through 
Chem Abstracts and don't hesitate to go way back.  With any luck, CA will 
point you to the particular Kruschev-era issue of Transactions of the 
Academy of Sciences of the Kazakh SSR that the parameter resides in.  If 
CA doesn't have a reference to it, it probably hasn't been measured.

Ben Buckner