1. Vincenzo Guidi Dipartimento di Fisica Università di Ferrara The sensors and semiconductors laboratory Dipartimento di Fisica Università di Ferrara - Italy INFM - INFN

2. Activities at the Sensors and semiconductors group Fundamental and applied research on nanostructured materials Fundamental and applied research on nanostructured materials Micromachining of microdevices Micromachining of microdevices Production and characterization of gas sensors and photovoltaic cells Production and characterization of gas sensors and photovoltaic cells

3. Matteo Ferroni Alessio Giberti Dario Gnani Vincenzo Guidi Cesare Malagù Federico Montoncello Marco Piga Alessandro Ronzoni Marco Stefancich Donato Vincenzi Overview Prof. Giuliano Martinelli Andrea Antonini Federico Bizzi Luca Bonazzi Mariangela Butturi Moira Buzzolani Maria Cristina Carotta Barbara Cavicchi Andrea Chiapatti Luigi Crema

5. 1 mm thick film the sensor 0 250 500 nm Powder preparation Thick film process paste preparation printing of the paste substratesubstrate temperature feed-back resistor platinum heater gold electrodes Chemoresistive gas sensors

6. 650 o C 850 o C Doping with tantalum (10 at.% ) TiO 2 gas sensing films 650 o C 850 o C 1  m 1.8 CO = 100 ppm wet air G gas /G air time (min) T = 400 o C 1.0 1.4 2.2 20 40 60 0 0 1  m

7. Comparison between conventional and innovative microsensors in CO detection Time (h) CO concentration (ppm) 8:0018:008:0018:000:000:001:00 Microsensor Conv. instrum.

8. Monitoring experiments in the frame of a project for evaluating the degradation level of the historical buildings in Ferrara Air quality assessment in urban environment…… Palazzo dei Diamanti 1 2 3 4

9. Microsensors deposited on a micro hotplate SiO 2 +Si 3 N 4 Insulating film Anisotropic etching SiO 2 +Si 3 N 4 Polysilicon resistor Low power consumption because of low thermal conductivity: 30 mW @ 400 ºC

10. Gas microsensors with hybrid technology

11. Traditionalgas-chromatografic with a capillary in fused silica 30 cm Miniaturized gas-cromatografic facility made of micromachined silicon 0,5 mm

12. High-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 P N ox P+ N+ 100  m