Premium
Efficiency Enhanced Hybrid Solar Cells Using a Blend of Quantum Dots and Nanorods
Author(s) -
Jeltsch Krischan F.,
Schädel Martin,
Bonekamp JörgBernd,
Niyamakom Phenwisa,
Rauscher Frank,
Lademann Hans W. A.,
Dumsch Ines,
Allard Sybille,
Scherf Ullrich,
Meerholz Klaus
Publication year - 2012
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201101809
Subject(s) - materials science , nanocrystal , nanorod , quantum dot , annealing (glass) , energy conversion efficiency , optoelectronics , photovoltaic system , hybrid solar cell , agglomerate , nanotechnology , polymer , chemical engineering , polymer solar cell , composite material , ecology , engineering , biology
The cell performance of organic‐inorganic hybrid photovoltaic devices based on CdSe nanocrystals and the semiconducting polymer poly[2,6‐(4,4‐bis(2‐ethylhexyl)‐ 4H ‐cyclopenta[2,1‐ b ;3,4‐ b′ ]‐dithiophene)‐ alt ‐4,7‐(2,1,3‐benzothiadiazole)] (PCPDTBT) is strongly dependent on the applied polymer‐to‐nanocrystal loading ratio and the annealing temperature. It is shown here that higher temperatures for the thermal annealing step have a beneficial impact on the nanocrystal phase by forming extended agglomerates necessary for electron percolation to enhance the short‐circuit current. However, there is a concomitant reduction of the open‐circuit voltage, which arises from energy‐level alterations of the organic and the inorganic component. Based on quantum dots and PCPDTBT, we present an optimized organic–inorganic hybrid system utilizing an annealing temperature of 210 °C, which provides a maximum power conversion efficiency of 2.8%. Further improvement is obtained by blending nanocrystals of two different shapes to compose a favorable n‐type network. The blend of spherical quantum dots and elongated nanorods results in a well‐interconnected pathway for electrons within the p‐type polmer matrix, yielding maximum efficiencies of 3.6% under simulated AM 1.5 illumination.