Chemistry Reference
In-Depth Information
The
neutral
insulator
TMTSF,
which
shows
field-effect
conduction
with
2cm
2
V
−
1
s
−
1
(Nam
et al.
, 2003), when transformed into a Bechgaard
salt also becomes superconducting, but at lower temperatures. In this case the
perfect segregation of organic and inorganic molecular planes leads to confined
electronic systems, which in the normal state are quasi 1D. Organic superconduc-
tors based on the BEDT-TTF molecule represent the case of pure 2D electronic
systems.
The fundamental question that many researchers have formulated is whether
a 2D electron gas can exhibit zero resistance below a given temperature, that is,
become superconducting. The answer seems to be positive if one thinks of the
BEDT-TTF salts or of the inorganic material MgB
2
but is not yet solved for arti-
ficial structures such as OFETs and inorganic superlattices, e.g., those involving
III-V semiconductors. This extremely interesting subject was, however, surrounded
by an unprecedented scandal in the year 2002, when it was proven that some articles
published in highly rated journals showing the discovery of superconductivity in
OFETs were false. The internal investigation conducted at Bell Laboratories, Lu-
cent Technologies proved scientific misconduct by the falsification or fabrication
of data.
3
For instance, anthracene and C
60
were claimed to become superconduc-
tors below 4 and 52 K, respectively, upon charge injection. Such articles were
retracted. This situation was very prejudicial for the scientific community and calls
for a profound reflection on the way some scientists are working or forced to
work (quick spectacular results and many publications seem to guarantee glory and
funding!).
4
At this point it should be made clear that the falsified data mainly concerned su-
perconductivity of organic semiconductors or insulators but not OFETs. It suffices
to read articles published before 2002, such as Garnier (1996). However, because
of the charge injection procedure involved, suspicion unfairly fell over the OFETs
community, a community that was rapidly incremented after the false claims. For-
tunately, it is rewarding to see that from about 2003 onwards, many research groups
have published several works on OFETs (some of them summarized in Table
6.1), showing that they pursued their research on this subject, and showing that
the quality of the semiconductor/insulator interfaces is improving. This is clearly
the way forward. However, since 2D electron systems can in principle become
µ
0
.
h
3
The full report of the investigation committee has been available at http://www.lucent.com/news events/
pdf/researchreview.pdf
4
D' etre plus qu' un homme, dans un monde d' hommes. Echapper a la condition humaine, vous disais-je. Non
pas puissant: tout-puissant. La maladie chimerique, donc la volonte de puissance n' est que la justification
intellectuelle, c' est la volont´ededeite: tout homme reve d' etre dieu.
To be more than a man, in a world of
men. To escape the human condition, I was saying to you. Not powerful: all-powerful. The visionary disease,
of which the desire for power is only the intellectual justification, is the desire for deity: every man dreams of
being god. Andre Malraux,
La condition humaine.
