A p- to n- transition on α-Fe₂O₃-based thick film sensors studied by conductance and work function change measurements, A.Gurlo, M.Sahm, A.Oprea, N.Barsan, U.Weimar, Sensors and Actuators B, 2004.

A n- to p- conductivity transition induced by oxygen adsorption on α-Fe₂O₃, A.Gurlo, N.Barsan, A.Oprea, M.Sahm, T.Sahm, U.Weimar, Applied Physics Letters, 85, 2004, 2280-2282.

Bioanalytical and Medical Trends in Sensor Applications; Organic layers for field effect application, A. Oprea, J. Claußen, C. Fietzek, M. Harbeck, H.-G. Mack and U. Weimar, Technology and Health Care, International Journal of Health Care Engineering, , Special Issue: Abstracts of ESEM 2003, 12/2, 2004, 139-142.

High Sensitivity Acid Films for Ammonia Detection with Field Effect Devices, A. Oprea, U. Weimar, Sensors and Actuators B, 111-112, 2005, 572-576.

Ammonia Detection Mechanism with Polyacrylic Acid Sensitive Layers: Field Effect Transduction, A. Oprea, N. Barsan, U. Weimar, Sensors and Actuators B, 111-112, 2005, 577-581.

Flip-Chip Gate Suspended Field Effect Transistors for Ammonia Detection, A. Oprea, E. Simon, M. Fleischer, H.-P. Frerichs, Wh. Wilbertz, M. Lehmann and U. Weimar, Sensors and Actuators B, 111-112, 2005, 582-586.

Conduction model of SnO₂ thin films based on conductance and Hall effect measurements, A. Oprea, E. Moretton, N. Barsan, W.J. Becker, J. Wöllenstein and U. Weimar, Journal of Applied Physics, 100, 2006, art. no. 033716.

Copper phthalocyanine suspended gate field effect transistors for NO₂ detection, A. Oprea, U. Weimar, E. Simon, M. Fleischer, H.-P. Frerichs, Ch. Wilbertz, M. Lehmann, Sensors and Actuators B, 118, 2006, 249-254.

Hybrid gas sensor platform based on capacitive coupled field effect transistors: Ammonia and nitrogen dioxide detection, A. Oprea, H.-P. Frerichs, Ch. Wilbertz, M. Lehmann and U. Weimar, Sensors and Actuators B, 127, 2007, 161-167.

Water and ammonia influence on the conduction mechanisms in polyacrylic acid films, M. Sahm, A. Oprea, N. Barsan and U. Weimar, Sensors and Actuators, B 127, 2007, 204-209.

Characterization of granular metal oxide semiconductor gas sensitive layers by using Hall effect based approaches, A. Oprea, N. Barsan and U. Weimar, J. Phys. D: Appl. Phys., 40, 2007, 7217-7237.

Interdependence of Ammonia and Water Sorption in Polyacrylic Acid Layers, M. Sahm, A. Oprea, N. Barsan, U. Weimar, Sensors & Actuators B, 130, 2008, 502-507.

Capacitive Humidity Sensors on Flexible RFID Labels, A.Oprea, N. Barsan, U. Weimar, M.-L. Bauersfeld, D. Ebling, J. Wöllenstein, Sensors & Actuators B, 132, 2008, 404-410.

Limitations on the use of perovskite-structure oxides in gas sensing as a result of the concurrent operation of separate mechanisms, P.T. Moseley, A. Oprea, O. Merdrignac-Conanec, M. Kerlau, N. Barsan, U.Weimar, Sensors and Actuators B 133, 2008, 543–546.

Kelvin Probe measurements of polymer coated gold substrates: Mechanism studies, M. Hoerter, A. Oprea, N. Barsan, U. Weimar, Sensors and Actuators B, 134, 2008, 266-272.

Chemical interaction of gaseous ammonia and water vapour with polyacrylic acid layers, M. Hoerter, A. Oprea, N. Barsan, U. Weimar, Sensors and Actuators B, 134, 2008, 743-749.

Transport and gas sensing properties of In₂O₃ nanocrystalline thick films: A Hall effect based approach, A. Oprea, A. Gurlo, N. Barsan, U. Weimar, Sensors and Actuators B, 139, 2009, 322-328.

Temperature, humidity and gas sensors integrated on plastic foil for low power applications, A. Oprea, J. Courbat, N. Barsan, D. Briand, N.F. de Rooij, U. Weimar, Sensors and Actuators B, 140, 2009, 227-232.

Work function changes in gas sensitive materials: Fundamentals and applications, A. Oprea, N. Barsan and U. Weimar, Sensors and Actuators B, 142, 2009.

Nonconventional phthalocyanines for field effect gas detection, W. Simmendinger, A. Oprea, N. Barsan, U. Weimar, Sensors and Actuators B: Chemical, Elsevier, 179, 2013, 54-60.

Contribution of polymeric swelling to the overall response of capacitive gas sensors, U. Altenberend, A. Oprea, N. Barsan, U. Weimar, Analytical and Bioanalytical Chemistry, Vol. 405, 2013, 6445-6452.

Towards fully printed capacitive gas sensors on flexible PET substrates based on Ag interdigitated transducers with increased stability, U. Altenberend, F. Molina-Lopez, A. Oprea, D. Briand, N. Barsan, N. F. De Rooij, U. Weimar, Sensors and Actuators B: Chemical, 187, 2013, 280-287.

Smart RFID label with a printed multisensory platform for environmental monitoring, A. Vásquez Quintero, F. Molina-Lopez, E. C. P. Smits, E. Danesh, J. van den Brand, K. Persaud, A. Oprea, N. Barsan, U. Weimar, N. F. de Rooij, D. Briand, Flexible and Printed Electronics , Vol.1,Nr.2, 2016, 1-12.

Characterization of granular metal oxide semiconductor gas sensitive layers by using Hall effect based approaches, A. Oprea, N. Barsan and U. Weimar, Article Cluster Sensors based on interfaces, J. Camassel, P. Soukiassian (Eds.), J. Phys. D: Appl. Phys., 40, 2007, 7217-7237.

Anomalous behaviour of a-Fe₂O₃-based thick film sensors studied by conductance and work function change measurements, A.Gurlo, M.Sahm, A.Oprea, N.Barsan, U.Weimar, Eurosensors XVII European Conference on Solid-State Transducers, 2003, 70-71, Guimaraes (Portugal).

Organic Layers for Field Effect Application, A. Oprea, J. Claußen, C. Fietzek, H.-G. Mack, M. Harbeck and U. Weimar, The 7th Conference of the European Society for Engineering and Medicine ESEM, 2003, 94, Halle, Germany.

n-typ Metalloxidsensoren werden zu p-typ Halbleitern: Liegt es an Adsorptionsvorgängen oder ist es die elektronische Struktur? Messung und Interpretation, M.Sahm, N.Barsan, A.Gurlo, A.Oprea, U.Weimar, 6.Dresdner Sensor Symposium, 2003, 19-22, Dresden (Germany).

Organic non-conducting materials as sensitive layers for field effect gas sensing, M. Harbeck, S. Riegelsberger, A. Oprea, N. Barsan, U. Weimar, 6.Dresdner Sensor Symposium, 2003, 153-156, Dresden (Germany).

Gas Sensing: Basic Understanding and Devices, U. Weimar, N. Barsan, A. Oprea, The 10th International Meeting on Chemical Sensors, 2004, 6-9, Tsukuba, Japan.

Simultaneous work function and conductance measurements on SnO₂ prepared from hydrothermally treated sols, A.Gurlo, T.Sahm, N.Barsan, A.Oprea, U.Weimar, N.Yamazoe, G.Sakai, K.Shimanoe, The 10th International Meeting on Chemical Sensors, 2004, 160-161, Tsukuba (Japan).

Flip-Chip Suspended Gate Field Effect Transistors for Ammonia Detection, Technical Digest of Eurosensors XVIII (2004) Rome, Italy, p18-19 and, A. Oprea, E. Simon, M. Fleischer, H.-P. Frerichs, Ch.Wilbertz, M. Lehmann, U. Weimar, Sensors and Actuators B, 111-112, 2005, p582-586.

Influence of different gas atmospheres on the mobility and the charge carrier concentration of SnO₂ thin films, E. Moretton, J. Wöllenstein, A. Oprea, N. Barsan, U.Weimar, Technical Digest of Eurosensors XVIII, 2004, 193-194, Rome, Italy.

High Sensitivity Polyacrylic Acid Films for Ammonia Detection with Field Effect Devices, A. Oprea, U. Weimar, Technical Digest of Eurosensors XVIII, 2004, 656-657, Rome, Italy.

Ammonia Detection Mechanism with Polyacrylic Acid Sensitive Layers: Field Effect Transduction, Technical Digest of Eurosensors XVIII, 2004, Rome, Italy p652-653, A. Oprea, N. Barsan, U. Weimar, and Sensors and Actuators B, 111-112, 2005, 577-581.

Copper Phthalocyanine Suspended Gate Field Effect Transistors for NO₂ Detection, A. Oprea, U. Weimar, E. Simon, M. Fleischer, H.-P. Frerichs, Ch. Wilbertz and M. Lehmann, Eurosensors XIX, 2005, Barcelona, Spain.

Versatile Charge Coupled Field Effect Transistor Platform for Hybrid Gas Sensors: Nitrogen Dioxide and Ammonia Detection, A. Oprea, H.-P.- Frerichs, Ch. Wilbertz, M. Lehmann and U. Weimar, Mikrosystemtechnik Kongress 2005, 2005, Freiburg.

Low power- low cost Gaseous Ammonia Sensors Based on Flip-Chip Suspended Gate Field Effect Transistors, A. Oprea, E. Simon, M. Fleischer, H.-P. Frerichs, Ch. Wilbertz, M. Lehmann and U. Weimar, Mikrosystemtechnik Kongress 2005, 2005, Freiburg.

Empfindliche Prozesse bei dünnen Polyacrylsäure-Schichten unter Ammoniak-Atmosphäre durch Impedanzspektroskopie aufgedeckt, M. Sahm, A. Oprea, N. Barsan and U. Weimar, 7. Dresdner Sensor-Symposium, Dresdner Beiträge zur Sensorik, Band 24, TUDpress,, 2005, 267-270, Dresden.

Gasempfindliche Polymer-Schichten zum Nachweis flüchtiger organischer Verbindungen: Fähigkeiten für kapazitive Auslesung, A. Oprea, S. Riegelsberger, M. Sahm, U. Weimar, 7. Dresdner Sensor-Symposium, Dresdner Beiträge zur Sensorik, Band 24, TUDpress, 2005, 25-28.

Interdependence of Ammonia and Water Sorption in Polyacrylic Acid Layers, M. Sahm, A. Oprea, N. Barsan and U. Weimar, The 11th International Meeting on Chemical Sensors, 2006, Brescia, Italy.

Hybrid Gas Sensor Platform based on Capacitive Coupled Field Effect Transistors: Ammonia and Nitrogen Detection, A. Oprea, H.-P. Frerichs, Ch. Wilbertz, M. Lehmann and U. Weimar, Eurosensors XX, 2006, 298-299, Goeteborg, Sweden, ISBN 978-91-631-9280.

Water and Ammonia Influence on the Conduction Mechanisms in Polyacrylic Acid Films, M. Sahm, A. Oprea, N. Barsan and U. Weimar, Eurosensors XX, 2006, 358-359, Goeteborg, Sweden, ISBN 978-91-631-9280.

Capacitive Humidity Sensors on Flexible RFID Labels, A. Oprea, N. Barsan, U. Weimar, M.-L. Bauersfeld, D. Ebling and J. Wöllenstein, Eurosensors XXI,10-14 June 2007, 2007, 2039-2042, Lyon, France.

Kapazitiver Feuchtesensor auf flexiblem Substrat, M.-L Bauersfeld, A. Oprea, N. Barsan, S. Rademacher, C. Matheis, U. Weimar and J. Wöllenstein, Mikrosystemtechnik Kongress 2007, 15-17 October, VDE-Verlag, 2007, 577-580, Dresden (Germany), ISBN 3-8007-3061-8.

Integrated temperature, humidity and gas sensors on flexible substrates for low-power applications, A. Oprea, J. Courbat, N. Bârsan, D. Briand, N.F. de Rooij, U. Weimar, Proceedings of IEEE Sensors Conference, Oct 28-31, 2007, 158-161, Atlanta, USA.

Opportunities and limitations in using combined electrical methods to characterise metal oxide semiconductors for gas sensing application: how and to which extent can be exploited the input from, investtigations performed in operando conditions towards pertinent information, A. Oprea, N. Barsan, U. Weimar, Conf. Proc. ASEVA Workshop, July 7-9, 2008, Salamanca, Spain.

Transport and Gas Sensing Properties of In₂O₃ Nanocrystalline Thick Films: A Hall Effect-based Approach, A. Oprea, A. Gurlo, N. Barsan, U. Weimar, Conf. Proc. 12th IMCS Conference July 13 - 16, 2008, Columbus, Ohio, USA.

Capacitive Gas Sensor Arrays on Plastic Substrates for Low Power and Mobile Applications, A. Oprea, U. Altenberend, J. Courbat, D. Briand, N. Barsan, U. Weimar, N.F. de Rooij, Conf. Proc. Eurosensors XXII, Sept. 7-10, 2008, 507, Dresden.

Multi Sensor Platform on Plastic Foil for Environmental Monitoring, J. Courbat, D. Briand, A. Oprea, N. Barsan, U. Weimar, N.F. de Rooij, Eurosensors XXII, September 6-9, 2009, Lausanne, Switzerland.

Evaluation of flexible substrates from commercially available plastic foils for capacitive gas sensors, U. Altenberend, F. Molina-Lopez, D. Briand, A. Oprea, N. Barsan, U. Weimar, N. F. De Rooij, International Symposium on Flexible Organic Electronics (ISFOE-11), 2011, Thessaloniki.

Untersuchung der Schichtdickenänderung dicker Polymerschichten geeignet für kapazitive Gassensoren, U. Altenberend, A. Oprea, N. Barsan, U. Weimar, 10. Dresdner Sensor-Symposium, 5-7 December, G. Gerlach, A. Schütze, TUDpress, 43, 2011, 249-252, Dresden.

Operando Untersuchungen der gas-sensorischen Eigenschaften von Metallphtalocyaninen durch kombinierte elektrische, optische und gravimetrische Messungen, W. Simmendinger, A. Oprea, N. Barsan, U. Weimar, 10. Dresdner Sensor-Symposium, 5-7 December, G. Gerlach, A. Schütze, TUDpress, 43, 2011, 131-132, Dresden.

Inkjet Printed Capacitive Transducers on Flexible Plastic Substrates with Increase Stability: Ag on PET, U. Altenberend, F. Molina-Lopez, D. Briand, A. Oprea, N. Barsan, N. F. De Rooij, U. Weimar, IMCS 2012 - The 14th International Meeting on Chemical Sensors,20-23 May, 2012, Nuremberg.