Correlation between surface photovoltage and blend morphology in polyfluorene-based photodiodes.
We present a microscopic study of photoinduced charge generation in polyfluorene-based photovoltaic structures. The sub-100 nm lateral resolution of scanning Kelvin probe microscopy allows characterizing the three-dimensional structure of thin films of blends of poly-(9,9'-dioctylfluorene-co-benzothiadiazole) (F8BT) and poly-(9,9'-dioctylfluorene-co-bis-N,N'-(4-butylphenyl)-bis-N,N'-phenyl-1,4-phenylenediamine) (PFB). From the strong correlation between surface photovoltage and blend morphology, we propose a simple model for the lateral and vertical film structure identifying in particular those regions with the most efficient conduction pathway for the photocurrent.
Chiesa
Marco
M
Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE, United Kingdom.
Bürgi
Lukas
L
Kim
Ji-Seon
JS
Shikler
Rafi
R
Friend
Richard H
RH
Sirringhaus
Henning
H