Читать книгу Fundamentals of Solar Cell Design - Rajender Boddula - Страница 21

The donor and acceptor molecules to be employed in BHJOSCs must have light absorption property matching the solar region, with high molar absorption coefficients and excellent width at half height of absorption spectrum. It would be best if absorption ranges of donor and acceptor materials are complementary.

The HOMO/LUMO energy levels of molecules should be well matched for the possible photochemical electron transfer between acceptor and donor molecules.

To obtain high open-circuit voltage (VOC), a deep HOMO level is to be adjusted, since maximum value of the VOC is determined by the energy difference between the HOMO level of the donor and LUMO level of the acceptor.

Balanced charge (negative and positive) mobility of the organic blend materials is required for controlled charge transport.

Good solubility of blend organic materials is essential for good film forming property and well mixing with acceptor materials to form nanoscale phase separation and ideal blend morphology.

Suitable recognition points may be introduced in blend materials, such that they can involve in forming supra-molecular structures leading to well organized film morphology, altered UV-visible absorption and providing good charge transport property.

Blend materials, higher thermal stability, and their phase transition temperature data are to be tuned properly.