Low Concentration Ammonia Detection Using Organic Field Effect Transistor Presented By Chandan Kumar Department of Electronics Engineering Prof. Satyabrata Jit & Prof. Rajiv Prakash Department of Electronics Engineering & School of Materials Science and Technology IIT (BHU) Varanasi India – IC-IMPACTS 2016 Summer Institute in Nanotechnology IC - IMPACTS Building Healthy Communities in Canada & India

Sensor or Detector Electronic processing Artificial Intelligence e- Sensing Natural sensing process  Development of room temperature, low cost and flexible sensor. Presence of ammonia is observed Objective & Motivations Experimental Process Results & Discussions Concluding Remarks  Highly sensitive and low concentration detection of ammonia.  Irritate eyes, Nose and throat & burning skin [1].  Maximum 8 hrs of 25 ppm NH 3 can cause chronic effects & max. 15 min of 35 ppm start irritate [2]. Impact of Ammonia  Sources of NH 3 are natural: decaying organics & excreta of organisms. Sources: 1.S. N. Behera et. al, Environ Sci Pollut Res, 20:8092–8131, Donham et al, J. Occup. Environ. Med. 42: , Outline

Film Deposition [1] PET ITO PVA : TiO 2 PQT-12 Au Sensible Area NH 3 Sensor Test Set-up Experimental Process  Lone electron pairs is captured by PQT-12 [2] OFET Structure Sources: 1.B. S. Ong et al, Journal of the American Chemical Society , , Rajiv K. Pandey et al, J. Phys. Chem. C, 118, 22943−22951, NH PQT-12 Molecules Carrier Holes Trapped Carriers

Output Curve : I D vs V DS Transfer Curve : I D vs V GS OFET Parameter Without NH 3 With NH 3 Mobility0.08 cm 2 /Vs 0.03 cm 2 /V s Threshold Voltage V- 8.3 V Drain Current Change by NH 3  Interaction of ammonia with polymer [1, 2] Increase Channel resistance Decrease in drain current Results and Discussions Source: 1.A. Salleo et al, Physical Review B 70, , Shashi Tiwari et al, Sensors and Actuators B 171– 172 (2012) 962– 968.  Two type of Interaction observed Chemical base dedoping, Physical dipole-charge interactions

Concluding Remarks Simple Solution based Technique Large Area Fabrication Low Temperature Processing Low Cost Technique Better than Metal Oxide Sensor Room Temp. Sensing ~ 50 % change in ID at -20 V for 25 ppm of NH3 Excellent Sensitivity Possibilities  Edge of flexibility  Sticker type device Suitable to wear Possible to use as curved sensors Thanks to Prof. S. Jit, Prof. R. Prakash, Gopal Rawat, Hemant Kumar & Yogesh Kumar for their continuous support & help. Thank You Everyone for Kind Attentions and Valuable Feedback