Introduction of a DNA interlayer adjacent to an Al cathode in a polymer light-emitting diode leads to lower turn-on voltages, higher luminance efficiencies, and characteristics comparable to those observed using a Ba electrode. The DNA serves to improve electron injection and also functions as a hole-blocking layer. The temporal characteristics of the devices are consistent with an interfacial dipole layer adjacent to the electrode being responsible for the reduction of the electron injection barrier.

The effect of molecular self-assembly on nanoscale photoinduced charge generation of fullerene-capped poly(3-hexylthiophene) (PCB-c-P3HT) films and its effectiveness as a molecular additive in bulk heterojunction P3HT:[6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM) is investigated through photoconductive atomic force microscopy. ortho-Dichlorobenzene-cast films of PCB-c-P3HT are found to form interconnected fibrous networks that show high photocurrent generation, while tetrahydrofuran-cast films show nanospheres with relatively low photocurrent generation. The nanofiber size and current generated from these nanowires are shown to vary with additions of PCBM. The PCB-c-P3HT amphiphile is shown to be a successful molecular additive in P3HT:PCBM films. These observations demonstrate how the self-assembly of PCB-c-P3HT into specific nanostructures is crucial to charge generation and transport.

A systematic evaluation of a novel conjugated polymer, bearing alkyl side chains on both the donor and acceptor units, is conducted using nanoscale characterization techniques and device fabrication. How to manage the use of solvent additives to achieve power‐conversion efficiencies of up to 3.7% is demonstrated.