A futuristic approach towards interface layer modifications for improved efficiency in inverted organic solar cells

Journal Article · Mon Jan 27 00:00:00 EST 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4863434· OSTI ID:22280529

Ali, Farman; Sharma, Abhishek; Chand, Suresh ^[1]; Pillai, Sriraj; Parakh, Sonal ^[1]

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1. Physics of Energy Harvesting Division (Organic and Hybrid Solar Cell Group), CSIR-National Physical Laboratory, CSIR-Network of Institutes for Solar Energy (NISE), Dr. K. S. Krishnan Marg, New Delhi 110012 (India)

Inverted polymer Solar Cells of the classical poly (3-hexylthiophene) (P3HT):(6,6)-phenyl-C{sub 61}butyric acid methyl ester (PC{sub 61}BM) blend on indium tin oxide substrates were fabricated, which shows improved device performance, by using a facile solution–processed ZnO-polyelectrolytes [poly (diallyldimethylammonium chloride) (PDADMAC), Poly (acrylic acid sodium salt) (PAS), poly (4-styrenesulfonic acid) (PSS), and Polyvinylpyrrolidone (PVP)] nanocomposite as a cathode interface layer compared to devices using pristine ZnO as cathode buffer layer in ambient conditions. The devices with different combinations of polyelectrolyte with ZnO show different improvements in the device efficiency. The combinations of ZnO with PVP and PDADMAC show highest amount of improvements in the efficiency by a factor of ∼17–19. The improvement of the efficiency may be due to various phenomena, such as the passivation of ZnO surface as well as bulk traps, work function modification, improved energy level alignment, improved electronic coupling of the inorganic/organic interface, improved light harvesting, and decrease of surface as well as bulk charge recombination in the device. The introduction of polyelectrolyte into ZnO inhibits the aggregation of ZnO nanoparticles yielding the large area ZnO nanoclusters; and hence, forming the uniform film of ZnO resulting in the modifications of morphology as well as electronic structure of ZnO-polyelectrolyte nano-composite favouring better electronic coupling between cathode and active layer and hence enhancing the current and, consequently, the efficiency. This simple low temperature ZnO-polyelectrolyte nanocomposite based protocol proposed for cathode interface layer modification may be very much useful for roll to roll industrial manufacturing of organic solar cells.

• OSTI ID: 22280529
• Journal Information: Applied Physics Letters, Vol. 104, Issue 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
ACRYLIC ACID
AMINO ACIDS
CATHODES
COMPARATIVE EVALUATIONS
COMPOSITE MATERIALS
ELECTRONIC STRUCTURE
ENERGY EFFICIENCY
ENERGY LEVELS
INDIUM COMPOUNDS
INTERFACES
LAYERS
NANOSTRUCTURES
ORGANIC SOLAR CELLS
PVP
THIN FILMS
TIN OXIDES
VISIBLE RADIATION
WORK FUNCTIONS
ZINC OXIDES