Vincenzo GuidiVincenzo Guidi

Dipartimento di FisicaDipartimento di FisicaUniversità di FerraraUniversità di Ferrara

The sensors and semiconductors laboratoryThe sensors and semiconductors laboratory

Dipartimento di Fisica Università di Ferrara - Italy

INFM - INFN

Activities at the Activities at the Sensors and semiconductors groupSensors and semiconductors group

• Fundamental and applied research on Fundamental and applied research on nanostructured materialsnanostructured materials

• Micromachining of microdevicesMicromachining of microdevices

• Production and characterization of gas sensors Production and characterization of gas sensors and photovoltaic cellsand photovoltaic cells

Matteo FerroniAlessio GibertiDario GnaniVincenzo GuidiCesare MalagùFederico MontoncelloMarco PigaAlessandro RonzoniMarco StefancichDonato Vincenzi

OverviewOverview

Prof. Giuliano MartinelliAndrea AntoniniFederico BizziLuca BonazziMariangela ButturiMoira BuzzolaniMaria Cristina CarottaBarbara CavicchiAndrea ChiapattiLuigi Crema

1 1 mmmm

thick thick filmfilm

the the sensorsensor

00 250250 500 500 nmnm00

250250

500500

00 250250 500 500 nmnm

Powder preparationPowder preparationPowder preparationPowder preparation

Thick film Thick film processprocess

Thick film Thick film processprocess

paste paste preparatipreparati

onon

paste paste preparatipreparati

onon

printing printing of the of the

pastepaste

printing printing of the of the

pastepaste

substratsubstratee

substratsubstratee

temperaturtemperature feed-back e feed-back

resistorresistor

platinum platinum heaterheater

gold gold electrodeselectrodes

Chemoresistive gas sensorsChemoresistive gas sensors

650 650 ooCC 850 850 ooCC

Doping with tantalum (10 at.Doping with tantalum (10 at.% )% )

Doping with tantalum (10 at.Doping with tantalum (10 at.% )% )

TiO2 gas sensing filmsTiO2 gas sensing films

650 650 ooCC 850 850 ooCC

1 1 m m

1.8

1.01.41.82.20204060TaTi-850oCTaTi-650oCTi-650oCTi-850oCCO = 100 ppm wet airCO = 100 ppm wet airCO = 100 ppm wet airCO = 100 ppm wet air

GGg

as

gas/G/G

air

air

GGg

as

gas/G/G

air

air

time time (min)(min)time time (min)(min)

T = 400 T = 400 ooCCT = 400 T = 400 ooCC

1.01.0

1.41.4

2.22.2

2020

4040 606000

1 1 m m 1 1 m m

1 1 m m

Comparison between conventional and innovative Comparison between conventional and innovative microsensors in CO detectionmicrosensors in CO detection

Time (h)Time (h)

CO

co

nce

ntra

tion

(p

pm

)C

O c

onc

ent

ratio

n (

pp

m)

8:008:00 18:0018:00 8:008:00 18:0018:000:000:00 0:000:001:001:000

0.5

1

1.5

2

2.5

3

3.5 MicrosensorMicrosensor

Conv. instrum.Conv. instrum.

Monitoring experiments in the frame Monitoring experiments in the frame of a project for of a project for evaluating the evaluating the degradation level of the historical degradation level of the historical buildings in Ferrarabuildings in Ferrara

Air quality assessment in urban environment……Air quality assessment in urban environment……

Palazzo dei Palazzo dei DiamantiDiamanti

11

22

33

44

Microsensors deposited on a micro hotplateSiO2+Si3N4

Insulating film

Anisotropicetching

SiO2+Si3N4

Polysilicon resistor

Low power consumption Low power consumption because of low thermal because of low thermal conductivity: 30 mW @ conductivity: 30 mW @

400 400 ººC C

Low power consumption Low power consumption because of low thermal because of low thermal conductivity: 30 mW @ conductivity: 30 mW @

400 400 ººC C

Gas microsensors with hybrid technologyGas microsensors with hybrid technology

TraditionalTraditionalgas-chromatograficgas-chromatografic

with a capillarywith a capillaryin in fused fused silicasilica

30 cm30 cm

Miniaturized gas-cromatografic Miniaturized gas-cromatografic facility made offacility made of

micromachined silicon micromachined silicon

0,5 mm0,5 mm

High-concentration photovoltaic solar cellsHigh-concentration photovoltaic solar cells

Mirrors are used to concentrate the radiation of the Sun on high-

efficiency PV cells.

PV cells are fabricated through microlithography

PP NNoxox

P+P+ N+N+

100 100 mm