Gas Sensing with Solar Cells: The Case of NH3 Detection through Nanocarbon/Silicon Hybrid Heterojunctions

Giovanni Drera; Sonia Freddi; Tiziano Freddi; Andrea De Poli; Stefania Pagliara; Maurizio De Crescenzi; Paola Castrucci; Luigi Sangaletti

doi:10.3390/nano10112303

Gas Sensing with Solar Cells: The Case of NH₃ Detection through Nanocarbon/Silicon Hybrid Heterojunctions

Nanomaterials (Basel). 2020 Nov 21;10(11):2303. doi: 10.3390/nano10112303.

Authors

Giovanni Drera¹, Sonia Freddi^{1

2}, Tiziano Freddi¹, Andrea De Poli¹, Stefania Pagliara¹, Maurizio De Crescenzi³, Paola Castrucci³, Luigi Sangaletti¹

Affiliations

¹ I-Lamp and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, via dei Musei 41, 25121 Brescia, Italy.
² Department of Chemistry, Division of Molecular Imaging and Photonics, KU Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium.
³ Dipartimento di Fisica, Università di Roma Tor Vergata, 00133 Roma, Italy.

Abstract

Photovoltaic (PV) cells based on single-walled carbon nanotube (SWCNT)/silicon (Si) and multiwalled carbon nanotube (MWCNT)/Si junctions were tested under exposure to NH₃ in the 0-21 ppm concentration range. The PV cell parameters remarkably changed upon NH₃ exposure, suggesting that these junctions, while being operated as PV cells, can react to changes in the environment, thereby acting as NH₃ gas sensors. Indeed, by choosing the open-circuit voltage, V_OC, parameter as read-out, it was found that these cells behaved as gas sensors, operating at room temperature with a response higher than chemiresistors developed on the same layers. The sensitivity was further increased when the whole current-voltage (I-V) curve was collected and the maximum power values were tracked upon NH₃ exposure.

Keywords: CNT/Si heterojunctions; NH3; PV cells; carbon nanotubes; gas sensing.