The ability to fabricate micro [1] and nanostructures [2] on silicon (Si) with the possibility to dope the final porous structures with noble metal NPs (e.g. gold, silver), using Metal-Assisted Etching (MAE)[3] is a unique advantage of MAE as to sensing applications. Over the standard fabrication technique such as anodic etching [4], MAE represents a low-cost room-temperature method for the synthesis of Si-based nanomaterials with peculiar sensing features, in terms of sensitivity and selectivity, towards specific gases, by bringing the catalytic properties and distinctive selectivity of the metals nanoparticles[5] and the widely tunable bandgap of the porous silicon into play. Here the prospect of using composite silicon/gold nanostructures (cSiAuN) prepared by MAE, gold-assisted, as highly sensitive material for adsorption of Nitrogen Dioxide (NO2) is proposed, examining the controllable high-yield integration of the material into solid-state devices. The controllable fabrication of the final nanostructures achieved by MAE approach leads to the fabrication of cSiAuN with high degree of control in terms of morphology of the pores and depth of the matrix, with enhanced sensing capabilities, which justifies their successful application in the preparation of chemi-transistor sensors, such as field-effect transistors, FETs, to be employed for gas sensing applications. As a case-of-study, we investigate the effective method for controllable integration of composite cSiAuN between electrodes of junction-field-effect transistors (JFET), aimed at the detection of NO2 down to 100 parts-per-billion (ppb). The resulting chemi-transistor sensor, cSiAuJFET (Composite Silicon Gold JFET), consists of a p-channel JFET in which the cSiAuN material is placed on top of the p-channel and acts as an extra floating gate and are responsible for the sensing capability of the JFET device. The cSiAuJFET sensors operate at room temperature and shows fast and reliable response to NO2 in the range 100-500 ppb without significant aging effects, in terms of baseline drift, response times, and sensitivity value, up to two days of continuous operation. The achieved approach presented in this work represent a guide for the possibility of employing MAE for gas sensing applications. [1] A. G. F. Owen J. Hildreth, Ching Ping Wong, ACSNano 2012, 6, 9. [2] L. Boarino, D. Imbraguglio, E. Enrico, N. De Leo, F. Celegato, P. Tiberto, N. Pugno, G. Amato, physica status solidi (a) 2011, 208, 1412. [3] Peng K. Q. et al. Advanced Materials 2002, 14, 1164. [4] G. M. Lazzerini, L. M. Strambini, G. Barillaro, Sci Rep 2013, 3, 1161. [5] L. C. Nicola Cioffi, Eliana Ieva, Rosa Pilolli, Nicoletta Ditaranto, Maria Daniela Angione, Serafina Cotrone, Kristina Buchholt, Anita Lloyd Spetz, Luigia Sabbatini, Luisa Torsi, Electrochimica Acta 2011, 56.
Chemi-Transistor Sensors based on Composite Silicon/Gold Nanostructures Prepared by Metal Assisted Etching
BARILLARO, GIUSEPPE
2014-01-01
Abstract
The ability to fabricate micro [1] and nanostructures [2] on silicon (Si) with the possibility to dope the final porous structures with noble metal NPs (e.g. gold, silver), using Metal-Assisted Etching (MAE)[3] is a unique advantage of MAE as to sensing applications. Over the standard fabrication technique such as anodic etching [4], MAE represents a low-cost room-temperature method for the synthesis of Si-based nanomaterials with peculiar sensing features, in terms of sensitivity and selectivity, towards specific gases, by bringing the catalytic properties and distinctive selectivity of the metals nanoparticles[5] and the widely tunable bandgap of the porous silicon into play. Here the prospect of using composite silicon/gold nanostructures (cSiAuN) prepared by MAE, gold-assisted, as highly sensitive material for adsorption of Nitrogen Dioxide (NO2) is proposed, examining the controllable high-yield integration of the material into solid-state devices. The controllable fabrication of the final nanostructures achieved by MAE approach leads to the fabrication of cSiAuN with high degree of control in terms of morphology of the pores and depth of the matrix, with enhanced sensing capabilities, which justifies their successful application in the preparation of chemi-transistor sensors, such as field-effect transistors, FETs, to be employed for gas sensing applications. As a case-of-study, we investigate the effective method for controllable integration of composite cSiAuN between electrodes of junction-field-effect transistors (JFET), aimed at the detection of NO2 down to 100 parts-per-billion (ppb). The resulting chemi-transistor sensor, cSiAuJFET (Composite Silicon Gold JFET), consists of a p-channel JFET in which the cSiAuN material is placed on top of the p-channel and acts as an extra floating gate and are responsible for the sensing capability of the JFET device. The cSiAuJFET sensors operate at room temperature and shows fast and reliable response to NO2 in the range 100-500 ppb without significant aging effects, in terms of baseline drift, response times, and sensitivity value, up to two days of continuous operation. The achieved approach presented in this work represent a guide for the possibility of employing MAE for gas sensing applications. [1] A. G. F. Owen J. Hildreth, Ching Ping Wong, ACSNano 2012, 6, 9. [2] L. Boarino, D. Imbraguglio, E. Enrico, N. De Leo, F. Celegato, P. Tiberto, N. Pugno, G. Amato, physica status solidi (a) 2011, 208, 1412. [3] Peng K. Q. et al. Advanced Materials 2002, 14, 1164. [4] G. M. Lazzerini, L. M. Strambini, G. Barillaro, Sci Rep 2013, 3, 1161. [5] L. C. Nicola Cioffi, Eliana Ieva, Rosa Pilolli, Nicoletta Ditaranto, Maria Daniela Angione, Serafina Cotrone, Kristina Buchholt, Anita Lloyd Spetz, Luigia Sabbatini, Luisa Torsi, Electrochimica Acta 2011, 56.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
