Luis F Fonseca

Dr. Luis F Fonseca


Research Focus & Metrics

Academic Career Length

43Years (1984-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 January 2014 in ACS Applied Materials & Interfaces
Verified
Journal Article
Closed access
JBJuan Beltran-Huarac
Juan Beltran-Huarac
OROscar Resto
Oscar Resto
JCJennifer Carpena-Nuñez
Jennifer Carpena-Nuñez
WJWojciech M. Jadwisienczak
Wojciech M. Jadwisienczak
LFLuis F Fonseca
Luis F Fonseca
RMray Morell
ray Morell

11 November 2013 in Journal of Applied Physics
Verified
Journal Article
Closed access
PDF file
LVL. A. Valentín
L. A. Valentín
JBJ. Betancourt
J. Betancourt
LFLuis F Fonseca
Luis F Fonseca
MPM. T. Pettes
M. T. Pettes
LSL. Shi
L. Shi
AHA. Huczko
A. Huczko
The temperature dependence of the Seebeck coefficient, the electrical and thermal conductivities of individual β-silicon carbide nanowires produced by combustion in a calorimetric bomb were studied using a suspended micro-resistance thermometry device that allows four-point probe measurements to be conducted on each nanowire. Additionally, crystal structure and growth direction for each measured nanowire was directly obtained by transmission electron microscopy analysis. The Fermi level, the carrier concentration, and mobility of each nanostructure were determined using a combination of Seebeck coefficient and electrical conductivity measurements, energy band structure and transport theory calculations. The temperature dependence of the thermal and electrical conductivities of the nanowires was explained in terms of contributions from boundary, impurity, and defect scattering.

1 November 1999 in Journal of Luminescence
Verified
Journal Article
Closed access
RSR.K. Soni
R.K. Soni
LFLuis F Fonseca
Luis F Fonseca
ORO. Resto
O. Resto
MBM. Buzaianu
M. Buzaianu
SWS.Z. Weisz
S.Z. Weisz

20 January 2014 in Scientific Reports
Verified
Journal Article
Open access
DYDachi Yang
Dachi Yang
JCJennifer Carpena-Núñez
Jennifer Carpena-Núñez
LFLuis F Fonseca
Luis F Fonseca
ABAzlin Biaggi-Labiosa
Azlin Biaggi-Labiosa
GHGary W. Hunter
Gary W. Hunter
For hydrogen sensors built with pure Pd nanowires, the instabilities causing baseline drifting and temperature-driven sensing behavior are limiting factors when working within a wide temperature range. To enhance the material stability, we have developed superlattice-structured palladium and copper nanowires (PdCu NWs) with random-gapped, screw-threaded, and spiral shapes achieved by wet-chemical approaches. The microstructure of the PdCu NWs reveals novel superlattices composed of lattice groups structured by four-atomic layers of alternating Pd and Cu. Sensors built with these modified NWs show significantly reduced baseline drifting and lower critical temperature (259.4[emsp14]K and 261[emsp14]K depending on the PdCu structure) for the reverse sensing behavior than those with pure Pd NWs (287[emsp14]K). Moreover, the response and recovery times of the PdCu NWs sensor were of ~9 and ~7 times faster than for Pd NWs sensors, respectively.

10 September 2012 in Small
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Journal Article
Closed access
PDF file
DYDachi Yang
Dachi Yang
LVLuis Valentín
Luis Valentín
JCJennifer Carpena
Jennifer Carpena
WOWilfredo Otaño
Wilfredo Otaño
OROscar Resto
Oscar Resto
LFLuis F Fonseca
Luis F Fonseca

10 August 2018 in Scientific Reports
Verified
Journal Article
Open access
PDF file
JHJose A. Hernandez
Jose A. Hernandez
ARAngel Ruiz
Angel Ruiz
LFLuis F Fonseca
Luis F Fonseca
MPMichael T. Pettes
Michael T. Pettes
MJMiguel Jose-Yacaman
Miguel Jose-Yacaman
ABAlfredo Benitez
Alfredo Benitez
Tin selenide (SnSe) has been the subject of great attention in the last years due to its highly efficient thermoelectricity and its possibilities as a green material, free of Pb and Te. Here, we report for the first time a thermoelectricity and transport study of individual SnSe micro- and nano-wires with diameters in the range between 130 nm and 1.15 μm. X-ray diffraction and transmission electron microscopy analyses confirm an orthorhombic SnSe structure with Pnma (62) symmetry group and 1:1 Sn:Se atomic ratio. Electrical and thermal conductivity and the Seebeck coefficient were measured in each individual nanowire using a specialized suspended microdevice in the 150–370 K temperature range, yielding a thermal conductivity of 0.55 Wm−1 K−1 at room temperature and ZT ~ 0.156 at 370 K for the 130 nm diameter nanowire. The measured properties were correlated with electronic information obtained by model simulations and with phonon scattering analysis. The results confirm these structures as promising building blocks to develop efficient temperature sensors, refrigerators and thermoelectric energy converters. The thermoelectric response of the nanowires is compared with recent reports on crystalline, polycrystalline and layered bulk structures.