Cover Picture: A Three‐dimensional Non‐fullerene Small Molecule Acceptor for Solution‐processed Organic Solar Cells (Chin. J. Chem. 11/2017)

The cover picture shows a new three‐dimensional non‐fullerene small molecular acceptor for solution‐processed organic solar cells. The acceptor was named SFTTIC using spiro‐bifluorene as the core unit linking with four thieno3,2‐b ]thiophenes and end‐capped with 2‐(3‐oxo‐2,3‐dihydro‐1H ‐inden‐1‐ylidene)malononitrile. SFTTIC has a high absorption coefficient, good thermal stability and appropriate energy levels and the optimized power conversion efficiency (PCE) of 5.66% was achieved for the devices with PBDB‐T as donor material. These results indicate that the 3D non‐fullerene small molecule is potential for achieving high photovoltaic performance. More details are discussed in the article by Chen et al. on page 1687–1692.