Thermally Activated n-Doping of Organic Semiconductors Achieved by N-Heterocyclic Carbene Based Dopant.

Molecular doping plays an important role in the modification of carrier density of organic semiconductors thus enhancing their optoelectronic performance. However, efficient n-doping remains challenging, especially owing to the lack of strongly reducing and air-stable n-dopants. Herein, an N-heterocyclic carbene (NHC) precursor, DMImC, is developed as a thermally activated n-dopant with the excellent stability in air. Its thermolysis in situ regenerates free NHC and subsequently dopes typical organic semiconductors. In sequentially doped FBDPPV films, DMImC does not disturb the π-π packing of the polymer and achieves good miscibility with the polymer. As a result, a high electrical conductivity of up to 8.4 S cm-1 is obtained. Additionally, the thermally activated doping and the excellent air stability permit DMImC to be noninteractively co-processed with polymers in air. Our results reveal that DMImC can be served as an efficient n-dopant suitable for various organic semiconductors.

A thermally activated and highly miscible dopant for n-type organic thermoelectrics.

N-doping plays an irreplaceable role in controlling the electron concentration of organic semiconductors thus to improve performance of organic semiconductor devices. However, compared with many mature p-doping methods, n-doping of organic semiconductor is still of challenges. In particular, dopant stability/processability, counterion-semiconductor immiscibility and doping induced microstructure non-uniformity have restricted the application of n-doping in high-performance devices. Here, we report a computer-assisted screening approach to rationally design of a triaminomethane-type dopant, which exhibit extremely high stability and strong hydride donating property due to its thermally activated doping mechanism. This triaminomethane derivative shows excellent counterion-semiconductor miscibility (counter cations stay with the polymer side chains), high doping efficiency and uniformity. By using triaminomethane, we realize a record n-type conductivity of up to 21 S cm-1 and power factors as high as 51 µW m-1 K-2 even in films with thicknesses over 10 µm, and we demonstrate the first reported all-polymer thermoelectric generator.

[The inhibitory effect of compound liuyuexue on DHBV DNA].

OBJECTIVE: To study the inhibitory effect of traditional Chinese medicine Compound Liuyuxeue(CLYX) on duck hepatitis B virus (DHBV) DNA, and provide experimental basis for developing a new drug for the clinical treatment. METHODS: One - day old Guangxi brown spotted ducks infected with DHBV were used as the hepatitis B virus infected animal model. Positive ducks were detected by PCR at 13 days after the infection of DHBV, and were randomly divided into five groups: the high dose group, middle dose group and low dose group of Compound Liuyexue( CLYX) , model group, positive control group. Every group had 10 ducks and CLYX was given for 14 days. The content of DHBV DNA in serum were measured by Fluoresceence Quantitative PCR( FQ-PCR). RESULTS: The serum DHBV DNA content was decreased significantly by the treatment with CLYX. The high dose group and middle dose group of CLYX could significantly inhibit DHBV DNA replication in vivo( P <0. 01). DHBV DNA content in serum in high dose group and middle dose group did not return significantly 3 days after stopping treatment, and its inhibitory effects were dose-and tim-dependents. CONCLUSION: CLYX can inhibit significantly DHBV DNA.