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Title: Bilayer Polymer Solar Cells with Improved Power Conversion Efficiency and Enhanced Spectrum Coverage

We demonstrate the construction of an efficient bilayer polymer solar cell comprising of Poly(3-hexylthiophene)(P3HT) as a p-type semiconductor and asymmetric fullerene (C{sub 70}) as n-type counterparts. The bilayer configuration was very efficient compared to the individual layer performance and it behaved like a regular p-n junction device. The photovoltaic characteristic of the bilayers were studied under AM 1.5 solar radiation and the optimized device parameters are the following: Voc = 0.5V, Jsc = 10.1 mA/cm{sup 2}, FF = 0.60 and power conversion efficiency of 3.6 %. A high fill factor of {approx}0.6 was achieved, which is only slightly reduced at very intense illumination. Balanced mobility between p-and n-layers is achieved which is essential for achieving high device performance. Correlation between the crystallinity, morphology and the transport properties of the active layers is established. The External quantum efficiency (EQE) spectral distribution of the bilayer devices with different processing solvents correlates well with the trends of short circuit current densities (J{sub sc}) measured under illumination. Efficiency of the bilayer devices with rough P3HT layer was found to be about 3 times higher than those with a planar P3HT surface. Hence it is desirable to have a larger grains with a rough surfacemore » of P3HT layer for providing larger interfacial area for the exciton dissociation.« less
Authors:
 [1] ;  [2]
  1. Department of Physics, Manipal Institute of Technology, Manipal University, Manipal, India 576 104 (India)
  2. Research Center for Applied Science, Academia Sinica, Taipei, Taiwan 300 13 (China)
Publication Date:
OSTI Identifier:
21612010
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1391; Journal Issue: 1; Conference: OPTICS 2011: International conference on light - Optics: phenomena, materials, devices, and characterization, Calicut, Kerala (India), 23-25 May 2011; Other Information: DOI: 10.1063/1.3646833; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 14 SOLAR ENERGY; CHARGE EXCHANGE; CORRELATIONS; CURRENT DENSITY; ENERGY CONVERSION; EXCITONS; FILL FACTORS; FULLERENES; ILLUMINANCE; LAYERS; MORPHOLOGY; ORGANIC POLYMERS; PHOTOVOLTAIC EFFECT; P-N JUNCTIONS; P-TYPE CONDUCTORS; QUANTUM EFFICIENCY; SOLAR CELLS; SOLAR RADIATION CARBON; CONVERSION; DIMENSIONLESS NUMBERS; DIRECT ENERGY CONVERTERS; EFFICIENCY; ELEMENTS; EQUIPMENT; MATERIALS; NONMETALS; ORGANIC COMPOUNDS; PHOTOELECTRIC CELLS; PHOTOELECTRIC EFFECT; PHOTOVOLTAIC CELLS; POLYMERS; QUASI PARTICLES; RADIATIONS; SEMICONDUCTOR JUNCTIONS; SEMICONDUCTOR MATERIALS; SOLAR EQUIPMENT; STELLAR RADIATION