Diapositiva 1

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CVD Diamond based Active Devices
Paolo Calvani
S2DEL Solid State and Diamond Electronics
Lab Università degli Studi Roma Tre
DiaC2Lab (Diamond Carbon Compounds Lab) IMIP -
CNR - Montelibretti (RM)
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Daniele M. Trucchi Paolo Calvani Alessandro
Bellucci Emilia Cappelli Stefano Orlando
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CNR-IMIP Know-How Projects
1989-1995 Study of Nucleation and Growth
Mechanisms of CVD Diamond 1995-1999 CVD
Diamond protective coatings of cutting
tools Coordination of MURST-CNR 5
Project 2003-2006 Development of high-tech
materials and ceramic coatings ENEA-MIUR
PROMOMAT Strategic Project 1999-2001 Secondar
y electron emission amplifiers for scanning
electron microscopy MADESS II Applied Research
Project 2000-2002 VUV DUV Radiation Detectors
in collaboration with S2DEL Univ. Roma Tre ASI
ARS1/R07/01 Aerospace Project 2001-2005 Poly-Diam
ond Radiation Dosimeters for Radiation Therapy
Coordination of European Project DIAMOND
G5RD-CT01-00603 2003-2007 Nanostructured Carbon
and graphene Structures for Opto-Electronic
applications FIRB Project Micro Nanocarbon
FISR Project High Density Memories 2008-2010 Sy
stems for direct nuclear-to-electric energy
conversion Coordination of CNR-RSTL
ECO-Diamond Project 2008-today Development of
Single-Crystal Diamond dosimeters in
collaboration with S2DEL - Univ. Roma
Tre 2010-2013 Thermionic-thermoelectric
conversion module for solar concentrated
systems E2PHEST2US Project
Mechanical Applications
Electronic Applications
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CNR-IMIP Facilities
Characterization of Chemical-Physical Properties
Characterization of Device Performance
Material Production
Technological Processes for Device Fabrication
Spectroscopy
Hot Filament CVD for diamond film deposition
Microwave CVD for diamond (doped) film deposition
Spectral Photometry
Microscopy
Pulsed laser (Excimer NdYAG) ablation for
(nanostructured) thin-film deposition of carbon,
carbides, refractory metals
Seebeck Effect Measurement System for
Thermoelectric Characterization
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Diamond Electronic Properties
Material Band gap Thermal conductivity Breakdown electric field Eb Mobility Carriers sat. velocity vsat Dielectric constant er
Material eV W/cmK 106 V/cm cm2/Vs 107 cm/s -
Diamond 5.5 20 10 2000 - h 1.0 5.7
Gallium nitride 3.4 1.5 2.5 2000 2.5 8.9
Silicon carbide 3.27 4.9 3.0 1000 2.0 9.7
Gallium Arsenide 1.42 0.55 0.4 8500 1.29 12.9
Silicon 1.12 1.5 0.3 1400 1.0 11.8
Germanium 0.67 0.58 0.1 3900 1.0 16.2

• High Frequency High Power Field Effect
  Transistors
• UV Power Switches
• Renewable Energies Conversion Stages

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High Frequency High Power Field Effect
Transistors
Plasma assisted Hydrogen termination of CVD
Diamond induces p-type conductive channel
Fabricated by S2DEL and IFN-CNR
Evolution of the band bending, activated by air
exposure, during the electron transfer process at
the interface between diamond and water layerb
density-of-states (DOS) is changing from 3D to
2D 2DHG
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RF Power Characterization by Politecnico di
Torino CLASS A _at_ 2GHz Pout0.2 W/mm Gain8
dB PAE21.3 Pout _at_ 1GHz 0.8 W/mma Best
result for Polycrystalline Diamond
LG200nm, WG50um VDS-14 V, VGS-0.3 V fMAX
15.2 GHz ft 6.2 GHz
Maximum VDS applied80 V Eapplied 2 MV/cm
Channel conductance is always positive. No self
heating effects!
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Polycrystalline Diamond PolyD4 by Russian Academy
of Sciences
Single Crystal Diamond P7MS by Russian Academy of
Sciences
Wg50 µm
-20 dB/dec.
WG25 µm
fMAX 26.3 GHz
fMAX 23.7 GHz
fT 6.9 GHz
fT 13.2 GHz
VGS-0.2 V, VDS-10 V
Eapplied 0.5 MV/cm
LG0.2 µm
RF Small Signal Characterization in collaboration
with by Tor Vergata University
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Polycrystalline Diamond PolyD4 by Russian Academy
of Sciences
Lg0.2 µm, Wg25 µm VGS0.0 V, VDS-35 V
-20 dB/dec.
fMAX 35 GHz
fT 10 GHz
Eapplied 1.75 MV/cm
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S2DEL
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UV POWER SWITCHES
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12/23
Source
Drain
G
UV generated carriers
diamond
VDS-9.6 V
VGS-3.4 V
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13/23
Source
Drain
G
UV generated carriers
diamond
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Renewable Energies Conversion Stage
EU Project E2PHEST2US

• Partners
• CNR (Italy, Scientific Coordination)
• CRR (Italy, Management Coordination)
• SHAP (Italy)
• Tel Aviv University (Israel)
• Tubitak (Turkey)
• Prysmian (Multinational Industry)
• Maya (San Marino)

• Duration 3 years (Jan 2010 - Jan 2013)
• Total Project Cost 2.68 M
• Total EU Funding 1.98 M

For details, http//www.ephestus.eu
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EU Project E2PHEST2US
Thermionic Stage Load
Radiation Absorber
Collector
Thermoelectric Stage Load
Rload
Rload
p
n
Under Vacuum
Concentrated Solar Radiation (400 1000 suns)
p
n
p
n
Thermionic Emitter
Inter-electrode Space (lt1 mm)

• Development of
• A radiation absorber made of ceramic materials
  able to work stably at high temperature (700 -
  1000 C)
• A thermionic conversion stage with CVD diamond as
  the active material
• A thermoelectric conversion stage constituted by
  high Seebeck coefficient materials
• Maximum theoretical efficiency 30

Final Thermal Stage
TR (700-1000 C)
Thermoelectric Stage
TE
TC (250-400 C)
TTE
TAmb
For details, http//www.ephestus.eu
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CVD Diamond based Active Devices
Thanks for the attention
S2DEL Solid State and Diamond Electronics
Lab Università degli Studi Roma Tre
DiaC2Lab (Diamond Carbon Compounds Lab) IMIP -
CNR - Montelibretti (RM)
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Alternative Technology in Concentrating Systems

• Multi-junction Photovoltaic Cells
• Thermodynamic Conversion by Heat Engines
  (Stirling, Rankine)

• Nominal Conversion Efficiency of 30
• Compactness
• No mechanical parts in movement

• Highly Expensive
• Mandatory Need of Cooling (Conversion Efficiency
  Exponentially Decreases with Temperature)
• Illumination Local Inhomogeneities Causes Output
  Bottlenecks
• Production Dependent on Semiconductor Industry
  (Few Large-Scale World Suppliers)

• Nominal Conversion Efficiency of 35 at High
  Temperatures (gt 600 C)

• Not Compact System
• Mechanical Parts in Movement (Degradation with
  Operative Time)
• Economically Reasonable for Large Plants (gt 10
  kWe)