Hybrid organic–inorganic porous semiconductor transducer for multi-parameters sensing

Porous silicon (PSi) non-symmetric multi-layers are modified by organic molecular beam deposition of an organic semiconductor, namely the N,N′-1H,1H-perfluorobutyldicyanoperylene-carboxydi-imide (PDIF-CN 2 ). Joule evaporation of PDIF-CN 2 into the PSi sponge-like matrix not only improves but also adds transducing skills, making this solid-state device a dual signal sensor for chemical monitoring. PDIF-CN 2 modified PSi optical microcavities show an increase of about five orders of magnitude in electric current with respect to the same bare device. This feature can be used to sense volatile substances. PDIF-CN 2 also improves chemical resistance of PSi against alkaline and acid corrosion.

Electronic Detection and Quantification of ions in solution using an a-Si:H Field-effect Device

Progress in microelectronics and semiconductor technology has enable new capabilities in the field of sensor construction, particularly of pH sensors based on field-effect transistors (FETs) as transducers of chemical signal. While crystalline devices present a higher sensitivity, their amorphous counterpart present a much lower fabrication cost, thus enabling the production of cheap disposable sensors for use in the food industry. Interest in biosensors consisting of a semiconductor transducer and a functionalized surface with biomolecule receptors (BioFET) continues to grow as they hold the promise for highly selective, label-free, real-time sensing as an alternative to conventional optical detection techniques. We have been involved in the development of a biosensor where the enzymatic activity of recombinant amidase from Escherichia coli is coupled to a semiconductor transducer for the detection of toxic amides in food and industrial effluents. The devices were fabricated on glass substrates by the PECVD technique in the top gate configuration, where the metallic gate is replaced by an electrolytic solution with an immersed Ag/AgCl reference electrode. Silicon nitride is used as gate dielectric enhancing the sensitivity and passivation layer used to avoid leakage and electrochemical reactions. In this article we report on the semiconductor unit, showing that the sensor displays the desired current-voltage characteristics. In addition we present an electrical model of the device, in agreement with the experimental data, that is sensitive to the pH of the solution.

Two-Parameter Semiconductor Transducer for Measuring High-Pressure and Temperature

ABSTRACTThe paper presents the results of studies on the application of semiconductor p-n junctions as two-parameter transducers of high-hydrostatic pressure and of temperature in the area of the pressure. A block diagram of an electronic circuit intended to collaborate with a two-parameter transducer has been given.