Project R-6195

Synthesis and characterization of distinct donor and acceptor small molecules to be used as semiconductors in bulk heterojunction ortganic solar cells (Research)

The general objective of this project can be defined as the development of a fundamental and profound understanding of the structure-property relationships of BHJ photovoltaic blends consisting of small molecules with a distinct and well-defined structure. For that purpose, a strong effort is planned on the synthesis of photoactive organic semiconductors with a basic structural composition containing alternating electron-poor (A) (Fig. 1) and electron-rich (D) (Fig. 2) building blocks and enhanced light-harvesting features (via extended conjugation and complementary subunits). It is expected, but subject of the planned investigations, that suitable electron donor molecules will rather be obtained from the D-A-D-A-D configuration, whereas the molecules with an A-D-A-D-A pattern will rather act as electron accepting materials (Fig. 3). At first instance, BHJ blends of the electron donor molecules with fullerenes (PC61BM/PC71BM) will be studied. Next, 2 blends will also be prepared from the most promising distinct molecular acceptor systems (combined with suitable donors). The blends will be characterized concerning their spectroscopic, thermal and electro-optical properties, specific blend morphologies that are obtained and their performance in OSC devices.

01 January 2016 - 30 June 2017