Synthesis and Dry Deposition of NanoCarbons for Flexible, Transparent Conducting Electrode (TCE) and Thin Film Field Effect Transistor (TFT-FET) Applications

Esko I. Kauppinen

NanoMaterials Group, Department of Applied Physics,
Aalto University School of Science and Technology

Puumiehenkuja 2, FI-02150 Espoo, Finland

esko.kauppinen@tkk.fi

We present mechanistic investigations on both single walled carbon nanotube (SWCNT) and carbon nanobud (CNB) formation mechanisms during floating catalyst synthesis from CO at ambient pressure and at temperature range 800-1100 oC using iron nanoparticle catalyst. Iron catalyst particles are produced in-situ into CO gas via both PVD and CVD methods. We introduce recent results on the synthesis of N-doped single walled tubes via introducing trace amounts of ammonia into CO during the synthesis. We discuss the effect of reactor operating temperature on the individual tube as well as bundle length and their diameter distributions, being determined both by electron microscopic as well as optical methods. Especially, we discuss the controll of tube chirality distributions via introducing trace amounts of CO2 and NH3 into the reactor.

Methods for SWCNT dry deposition at ambient temperature to manufacture transparent thin film field effect transistor (TFT) with high carrier mobility as compared to organic semiconductors and transparent, flexible thin film conducting electrode (TCE) with sheet resistance comparable or even lower than low temperature deposited ITO on PET polymer will be discussed. We show that the most important SWCNT property controlling the conductivity of the SWCNT-based TCE is the nanotube bundle length. Also, we show present recent results on TFT-FETs based on percolating SWCNT networks and discuss the effect of ALD deposited metal oxide passivation layer on the transistor characteristics.

CV-Esko Kauppinen.pdf