Synergic effects of conducting polymers, carbon nanotubes, and graphene result in the enhanced thermoelectric properties of nanocomposites.

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been studied for a wide range of applications due to its potential as a transparent electrode. Herein, the use of imidazole and its derivatives as a neutralizing additive for PEDOT:PSS dispersion and in-depth studies of their effects in terms of electrical properties and stability is reported. Although the neutralization in general reduces the electrical conductivity of PEDOT:PSS, the conductivity after imidazole treatment (685.2 S cm 21 ) is higher than that after treatment of other derivatives. Spectroscopic and thermoelectric studies show that the de-doping effect resulted in the conductivity reduction. As a trade-off of the conductivity reduction, greatly enhanced long-term stability and noncorrosive characteristics are obtained after neutralization. The change in sheet resistance of imidazole-treated PEDOT:PSS after 500 h under harsh conditions (85 8C and 85% humidity) is half that of the untreated samples, demonstrating the great enhancement of the stability.

Poly(3,4-ethyldioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), as an thermoelectric(TE) material, exhibits a high electrical conductivity and ZT value (10 À1 -10 0 ). Nevertheless, a low thermovoltage of the organic thermoelectric materials must be overcome, in comparison to that of semi metals. Recently, to address these challenges, several researchers have investigated PEDOT:PSS/carbon material composites.Herein, a transparent and flexible hybrid film made up of rapid thermal chemical vapor deposition (RTCVD) graphene and PEDOT:PSS results in enhanced TE performance. The PEDOT:PSS was synthesized by oxidative polymerization, and the hybrid process of the graphene film and PEDOT:PSS film was conducted using the layer-by-layer method. The results of AFM and Raman spectroscopy revealed that the synergistic effect through composite films improved the electrical properties. The maximum electrical conductivity and power factor of the RTCVD graphene/PEDOT:PSS (RCG/P) hybrid film were 1096 S cm À1 and 57.9 mW m À1 K À2, respectively. In addition, the RCG/P hybrid film exhibited excellent mechanical flexibility and stability.

For the first time, the 3 dimensionally stacked NAND Flash memory, is developed by implementing S 3 ( Single-crystal Si layer Stacking ) technology, which was used to develop S 3 SRAM previously. The NAND cell arrays are formed on the ILD as well as on the bulk to double the memory density without increasing the chip size. The feasibility of the technology was proven by the successful operation of 32 bit NAND Flash memory cell strings with 63nm dimension and TANOS structures. The novel NAND cell operational scheme, so called SBT ( Source-Body Tied) scheme, is presented to maximize the advantages of 3 dimensionally stacked NAND cell structures.

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