Scientist recommend new approach for interfacial adjustment of organic solar cells

• Surface area energy (γs) plays a key function in the development of bulk-heterojunction (BHJ) films in organic solar cells fabricated by solution process. The miscibility of BHJ films can be forecasted by the difference of surface area power in between donor and acceptor.

The vertical distribution and the piling orientation of BHJ films can be managed by the surface area power in the bottom user interface layer. The surface area energy of thin film is usually gotten by gauging call angle making use of Owens-Wendt version.

However, this measurement approach can not show the surface area power circulation in the nanoscale range, as well as it can not straight clarify the nanoscale stacking and phase splitting up in the BHJ framework.

Recently, a research group led by Profs. Zhou Huiqiong, Qiu Xiaohui and also Zhang Yong from the National Center for Nanoscience as well as Technology (NCNST) of the Chinese Academy of Sciences (CAS) proposed a new approach to explore the regulation of nanoscale surface energy circulation at the user interface layer of organic solar cells. The research study was published in Joule.

The researchers utilized the AFM-based Peak-Force Quantitative Nanomechanical Mappings (PFQNM) strategy to define the nanoscale surface energy distribution of hole carrying layers in organic solar cells. They discovered that the surface area energy distribution of poly3, 4-ethylenedioxythiophene: polystyrene sulfonate (PEDOT: PSS) can be efficiently regulated by doping MoS2 nanosheets with various side dimensions and also the heterogeneity of PEDOT: PSS circulation can be bigger. The heterogeneous distribution of surface area energy (HeD-SE) can better regulate the molecular circulation, crystal alignment and phase separation of the active layer.

Due to the optimization of the energetic layer morphology by the HeD-SE, the performance and also security of organic solar cells were improved with the most effective power conversion effectiveness (PCE) of 18.27%. Besides, the improvement ratio of PCE was proportional to the enlargement of Δγs in the BHJ.

Prof. Zhou's team has been devoted to the interface adjustment in solution-processed organic solar cells, and has accomplished a series of researches on the surface energy guideline in organic solar cells. The scientists first accomplished a high fill aspect of 80% in organic solar cell by including WOx nanoparticles in PEDOT: PSS. Then they checked out the partnerships between the piling alignment of the active layer, the performance of organic solar cells and the surface area power of the interface layer. The approach of interfacial adjustment was utilized to examine electron delivering layer in upside down devices, and also has been utilized in perovskite solar cells. By utilizing the biopolymer heparin salt to customize the surface power, the interface issue of perovskite solar cells was passivated with enhancements of PCE and also security.