Observation of a Charge Transfer State in Low-Bandgap Polymer/Fullerene Blend Systems by Photoluminescence and Electroluminescence Studies
Artikel i vetenskaplig tidskrift, 2009

The presence of charge transfer states generated by the interaction between the fullerene acceptor PCBM and two alternating copolymers of fluorene with donor-acceptor-donor comonomers are reported; the generation leads to modifications in the polymer bandgap and electronic structure. In one of polymer/fullerene blends, the driving force for photocurrent generation, i.e., the gap between the lowest unoccupied molecular orbitals of the donor and acceptor, is only 0.1 eV, but photocurrent is generated. It is shown that the presence of a charge transfer state is more important than the driving force. The charge transfer states are visible through new emission peaks in the photoluminescence spectra and through electroluminescence at a forward bias. The photoluminescence can be quenched under reverse bias, and can be directly correlated to the mechanism of photocurrent generation. The excited charge transfer state is easily dissociated into free charge carriers, and is an important intermediate state through which free charge carriers are generated.

Författare

[Person 7f089de1-fa15-45e2-a2d5-6c7e72272b28 not found]

Linköpings universitet

[Person 1e5cc83b-3b4d-4ec9-9fd3-e1f0668f4b03 not found]

Linköpings universitet

[Person 14878e22-c720-47d3-91cc-c5678ff6feba not found]

Linköpings universitet

[Person 1d41471e-9278-4c18-a83d-bf25777cf6a1 not found]

Linköpings universitet

[Person 5ef5ccce-3475-4c44-be25-808a342f0632 not found]

Linköpings universitet

[Person 121d083b-03fe-44ff-8d1c-c38919ee4535 not found]

Chalmers, Kemi- och bioteknik, Polymerteknologi

[Person 823293bb-d9c3-4867-91ee-b662fb2829b7 not found]

Linköpings universitet

Advanced Materials for Optics and Electronics

1057-9257 (ISSN) 1616-3028 (eISSN)

Vol. 19 20 3293-3299

Ämneskategorier

Polymerkemi

DOI

10.1002/adfm.200900702

Mer information

Senast uppdaterat

2018-02-28