Ultrafast Terahertz Photoconductivity of Bulk Heterojunction Materials Reveals High Carrier Mobility up to Nanosecond Time Scale

• The few-picosecond (ps) decay of terahertz (THz) photoconductivity typically observed for conjugated polymer fullerene blends (at excitation fluencies similar to 10(15) photons/cm(2) per pulse) is shown to be a result of charge pair annihilation for two polymer:PCBM blends. At a factor of 100 lower excitation density, the THz decay is in the hundreds of ps time scale, implying that very high carrier mobility (similar to 0.1 cm(2) V-1 s(-1)) prevails for long time after charge formation, of importance for free charge formation in organic solar cells.

Subject headings

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

NATURVETENSKAP  -- Kemi -- Annan kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Other Chemistry Topics (hsv//eng)

Keyword

blends

dynamics

photogeneration

alternating polyfluorene copolymer

polymer solar-cells

geminate charge recombination

spectroscopy

Publication and Content Type

art (subject category)

ref (subject category)