Marcel Bouvet: Molecular material-based gas sensors 3 - Electrochemistry as a source of tuning and novelty

The lecture shows how we can tune the electrical and sensing properties of organic heterojunction devices built on ITO electrodes and made from a low conductive sub-layer (e.g. Cu(F16Pc)) covered by a highly conductive semiconductor (LuPc2), by electrografting of organic layers before depositing the sublayer. Impedance spectroscopy clearly demonstrates the increase of the energy barrier at the ITO – sublayer interface. The I(V) characteristics of the heterojunctions are highly modified by the electrografting. One important feature is that the sensing properties are highly improved compared to the unmodified devices. Thus, the electrografting of dimethoxybenzene doubles the relative response of the heterojunction towards 90 ppm NH3, as well as the sensitivity in the range 1–9 ppm. Beside, poor conducting polymers (polytetrafluoroaniline, polyporphyrins and polycorroles) were electrodeposited and covered by a highly conducting material, leading to double lateral heterojunctions. They were also studied as sensing devices for the detection of ammonia, at room temperature and in a broad range of relative humidity
 

Prof. Marcel Bouvet prepared his Ph.D. at the École supérieure de physique et de chimie industrielles (ESPCI Paris) and received his Ph.D. on the electrical properties of phthalocyanines from the University Pierre and Marie Curie (UPMC) in 1992. He has worked mainly at the ESPCI as an associate professor and has also worked at the UPMC (Paris) and the University of Connecticut (USA). He started a full professor position at the University of Burgundy (Dijon, France) in 2008 where he is currently the head of the department Synthesis, Environment and Materials (SEM) in the Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB). His research interests are in the field of molecular materials, semiconductors and charge transfer complexes, conductometric transducers, organic electronics, and chemical sensors.