http://www.cnr.it/ontology/cnr/individuo/prodotto/ID33863

Controlling Semiconductor/Metal Junction Barriers by Incomplete, Nonideal Molecular Monolayers (Articolo in rivista)

Type

Articolo in rivista (Classe)
Prodotto della ricerca (Classe)

Label

Controlling Semiconductor/Metal Junction Barriers by Incomplete, Nonideal Molecular Monolayers (Articolo in rivista) (literal)

Anno

2006-01-01T00:00:00+01:00 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi

10.1021/ja058224a (literal)

Alternative label

Hossam Haick (a); Marianna Ambrico(b);Teresa Ligonzo(c); Raymond T. Tung(d); and David Cahen(e) (2006)
Controlling Semiconductor/Metal Junction Barriers by Incomplete, Nonideal Molecular Monolayers
in Journal of the American Chemical Society (Print); ACS, American chemical society, Washington, DC (Stati Uniti d'America)
(literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori

Hossam Haick (a); Marianna Ambrico(b);Teresa Ligonzo(c); Raymond T. Tung(d); and David Cahen(e) (literal)

Pagina inizio

6854 (literal)

Pagina fine

6869 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume

128 (literal)

Rivista

Journal of the American Chemical Society (Rivista)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroFascicolo

21 (literal)

Note

ISI Web of Science (WOS) (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni

(a)Chemical Engineering, Technion, Haifa 32000, Israel. (b) CNR-IMIP Sezione di Bari. (c) Universita' degli Studi di Bari and INFM. (d) City University of New York. (e)Weizmann Institute of Science. (literal)

Titolo

Controlling Semiconductor/Metal Junction Barriers by Incomplete, Nonideal Molecular Monolayers (literal)

Abstract

We study how partial monolayers of molecular dipoles at semiconductor/metal interfaces can affect electrical transport across these interfaces, using a series of molecules with systematically varying dipole moment, adsorbed on n-GaAs, prior to Au or Pd metal contact deposition, by indirect evaporation or as \"ready-made\" pads. From analyses of the molecularly modified surfaces, we find that molecular coverage is poorer on low- than on high-doped n-GaAs. Electrical charge transport across the resulting interfaces was studied by current-voltage-temperature, internal photoemission, and capacitance-voltage measurements. The data were analyzed and compared with numerical simulations of interfaces that present inhomogeneous barriers for electron transport across them. For high-doped GaAs, we confirm that only the former, molecular dipole-dependent barrier is found. Although no clear molecular effects appear to exist with low-doped n-GaAs, those data are well explained by two coexisting barriers for electron transport, one with clear systematic dependence on molecular dipole (molecule-controlled regions) and a constant one (molecule-free regions, pinholes). This explains why directly observable molecular control over the barrier height is found with high-doped GaAs: there, the monolayer pinholes are small enough for their electronic effect not to be felt (they are \"pinched off\"). We conclude that molecules can control and tailor electronic devices need not form high-quality monolayers, bind chemically to both electrodes, or form multilayers to achieve complete surface coverage. Furthermore, the problem of stability during electron transport is significantly alleviated with molecular control via partial molecule coverage, as most current flows now between, rather than via, the molecules. (literal)

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