| 초록 |
A novel small molecule (PDTP-WR) with a dithieno[3,2-b:2′,3′-d]phosphole oxide (DTP) core unit was synthesized for use in BHJ solar cells. This small molecule had an optical band gap of 1.65 eV, appropriate for a donor material, and HOMO and LUMO energy levels of –5.10, and –3.45 eV, respectively, which provided a broad absorption and superior charge transfer properties. The solar cell devices employing PDTP-WR and PC71BM gave a promising power conversion efficiency of 5.04%, a Jsc of 12.98 mA cm–2, a Voc of 0.79 V, and a fill factor of 49%, without pre- or post-treatments. Morphological studies revealed that the favorable blend morphology with an appropriate domain size of less than 20 nm and bi-continuous interpenetrating paths having an ordered structure can support the device performances. This is the first reported use of DTP in small molecule donor, and the results indicated that DTP-based small molecule can be a promising candidate for the photovoltaic applications. |
