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Near‐Infrared Electric Power Generation Through Sub‐Energy‐Gap Absorption in an Organic–Inorganic Composite
Author(s) -
Ng TszWai,
Lo MingFai,
Yang QingDan,
Fung ManKeung,
Lee ChunSing
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.201200058
Subject(s) - rubrene , materials science , optoelectronics , exciton , band gap , absorption (acoustics) , molybdenum trioxide , excitation , energy harvesting , nanotechnology , energy (signal processing) , molybdenum , physics , condensed matter physics , quantum mechanics , metallurgy , composite material
Exploitation of energy from the near‐infrared (NIR) region is one strategic approach for enhancing the performance of organic photovoltaic devices (OPVs). While effort has been mostly put toward developing materials with narrow energy gaps, here, a simple approach for harvesting NIR photons with wide‐energy‐gap materials by making use of their interactive charge‐transfer complex (CTC) is shown. It is shown using photoemission studies that the interface between molybdenum (VI) oxide and 5,6,11,12‐tetraphenylnaphthacene (MoO 3 /rubrene) possesses an abrupt discontinuity in the vacuum level (VL), resulting in significantly overlapped electron wavefunctions and CTC formation. The CTC induces an intermediate state within the original energy gap of rubrene with energy of ≈1.3 eV, suggesting the feasibility of a charge transfer (CT) exciton generated upon NIR excitation. This is confirmed by generation of electric power OPVs with an active layer of MoO 3 :rubrene composite under excitation with a NIR light source.