Cross Kelvin force microscopy and conductive atomic force microscopy studies of organic bulk heterojunction blends for local morphology and electrical behavior analysis

Journal Article · Sat Feb 07 00:00:00 EST 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4907213· OSTI ID:22413069

Le Borgne, D. ^[1]; Bedel-Pereira, E.; Séguy, I. ^[2]; Moineau Chane-Ching, K. I.; Hernandez-Maldonado, D. ^[2]

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1. LAPLACE, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse (France)
2. UPS, INPT, Université de Toulouse, LCC 31077 Toulouse (France)

Bulk Heterojunction (BHJ) organic photovoltaic devices performances depend on the relative organization and physical properties of the electron-donor and -acceptor materials. In this paper, BHJs of poly(3-hexyl-thiophene) (P3HT) associated with an electron acceptor material, 1-(3-methoxycarbonyl)-propyl-1-phenyl[6,6]C6 (PCBM) or [Ni(4dodpedt){sub 2}], are studied in terms of morphology, ordering, and electrical properties. First, comparison between the two BHJs performed by Atomic Force Microscopy (AFM) and Raman characterizations shows that P3HT structuration is improved by blending with [Ni(4dodpedt){sub 2}]. Then, the relationship between charges trapping, electrical properties, and film morphology is investigated using conductive AFM and Kelvin Force Microscopy. Measurements in dark condition and under solar cell simulator provide complementary information on electrical phenomena in these organic nanostructures. Finally, time dependent measurement highlights the influence of charges stacking on conduction. Specifically, we demonstrate that charge accumulation initiated by illumination remains valid after switching off the light, and induces the modification in current versus voltage characteristic of P3HT: PCBM blend. Finally, we observe a current increasing which can be attributed to the energy barrier decreasing due to charges trapping in PCBM.

• OSTI ID: 22413069
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 5; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMIC FORCE MICROSCOPY
BINDING ENERGY
COMPARATIVE EVALUATIONS
ELECTRIC CONDUCTIVITY
ELECTRONS
FILMS
HETEROJUNCTIONS
ILLUMINANCE
MORPHOLOGY
NANOSTRUCTURES
PHOTOVOLTAIC EFFECT
POLYCYCLIC SULFUR HETEROCYCLES
SOLAR CELLS
THIOPHENE
TIME DEPENDENCE
TRAPPING
VALENCE