Utilization of colloidal semiconductor nanocrystals for high performance thin film electronic/optoelectronic devices has been an emerging research topic over the last few decades.  Beyond the well-known size-tunable physical properties of inorganic semiconductors, the capability of forming colloidal dispersions in conventional solvent offers great promise for large-area, low cost printed electronics. In this presentation, we introduce the utilization of well-define colloidal CdSe semiconductor nanocrystals in tetrapod structure for transistors and solar cells applications. Colloidal tetrapod CdSe nanocrystals with tunable arm length (30 � 90 nm) were prepared via the continuous precursor injection (CPI) methods with excellent shape selectivity. Beakwater-like networks of CdSe nanocrystals could then be formed by spin-coating the colloidal dispersions of tetrapod nanocrystals. The extended structure of tetrapod nanocrystals with long arms provided unique characteristics to the resulting networks. The porous nature of the nanocrystal networks allowed hybridizing the networks with other functional materials. For example, infusing poly(3-hexylthiophene) (P3HT) into the CdSe networks formed pn-organic/inorganic hybrid bulk heterojunctions, resulting in solar cells with a power conversion efficiency up to 2.2%. Also, the introduction of ionic liquids such as (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) into the networks enabled modulating the conductivity and mobility of the networks through the electrochemical gating process. The electron mobility of such systems was found to be dependent upon tetrapod arm length and the value as high as 5 cm2/Vs was attained. We believe that the utilization of tetrapod-structured nanocrystals provides new strategies to realize low-cost and flexible electronics.

Colloidal tetrapod semiconductor nanocrystals for electronic/optoelectronic applications

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.