Dipartimento di Fisica
Università di Ferrara - Italy
INFM - INFN
The sensors and semiconductors laboratory
Vincenzo Guidi
Dipartimento di Fisica
Università di Ferrara
Activities at the
Sensors and semiconductors group
• Fundamental and applied research on
nanostructured materials
• Micromachining of microdevices
• Production and characterization of gas sensors
and photovoltaic cells
Overview
Prof. Giuliano Martinelli
Andrea Antonini
Federico Bizzi
Luca Bonazzi
Mariangela Butturi
Moira Buzzolani
Maria Cristina Carotta
Barbara Cavicchi
Andrea Chiapatti
Luigi Crema
Matteo Ferroni
Alessio Giberti
Dario Gnani
Vincenzo Guidi
Cesare Malagù
Federico Montoncello
Marco Piga
Alessandro Ronzoni
Marco Stefancich
Donato Vincenzi
Chemoresistive gas sensors
Powder preparation
gold
electrodes
500
250
0
0
250
250
paste
preparation
Thick film
process
0
500 nm
substrate
temperature
feed-back
resistor
platinum
heater
500 nm
printing of
the paste
1 mm
thick film
the sensor
TiO2 gas sensing films
650
oC
850 oC
CO = 100 ppm wet air
o
TaTi-850 C
o
TaTi-650 C
o
Ti-650 C
o
Ti-850 C
1  m
1  m
Ggas/Gair
2.2
2.2
1.8
Doping with tantalum (10 at.% )
650 oC
850 oC
T = 400 oC
1.8
1.4
1.4
1.0
1.0
1  m
1  m
00
20
40
20
40
time (min)
60
60
Comparison between conventional and innovative
microsensors in CO detection
CO concentration (ppm)
3.5
Microsensor
Conv. instrum.
3
2.5
2
1.5
1
0.5
0
1:00
8:00
18:00
0:00
Time (h)
8:00
18:00
0:00
Monitoring experiments in the frame of a
project for evaluating the degradation
level of the historical buildings in Ferrara
3
2
1
4
Air quality assessment in urban environment……
Palazzo dei
Diamanti
Microsensors deposited on a micro hotplate
SiO2+Si3N4
SiO2+Si3N4
Polysilicon
resistor
Insulating film
Low power consumption
because of low thermal
conductivity: 30 mW @
400 ºC
Anisotropic
etching
Gas microsensors with hybrid technology
Traditional
gas-chromatografic
with a capillary
in fused silica
30 cm
Miniaturized gas-cromatografic
facility made of
micromachined silicon
0,5 mm
High-concentration photovoltaic solar cells
100 m
Mirrors are used to concentrate the
radiation of the Sun on highefficiency PV cells.
PV cells are fabricated through
microlithography
P
N
ox
P+
N+