Zhong Xinhua and Li Yan of East China University of science and technology successfully assembled multi-component co sensitized quantum dot solar cells with photoelectric conversion efficiency of more than 12%

Recently, the school of chemistry and molecular engineering of East China University of science and technology has made important progress in the field of quantum dot sensitized solar cell (qdsc) device research, and published an article entitled "co sensitive quantum dot solar cells with conversion efficiency of 12%" (adv mater 2018, DOI: 10.1002/adma.201705746), with Wang Wei as the first author The research work was completed under the guidance of Associate Professor Li Yan and supported by Professor Zhong Xinhua High cost performance solar cell is one of the effective ways to alleviate the energy crisis Qdsc is a kind of sensitized solar cell with semiconductor nanocrystals as light trapping materials In recent years, qdsc has developed rapidly, and its photoelectric conversion efficiency has increased from 5% in 2012 to 12% at present Although the efficiency obtained is comparable to that of the traditional dye-sensitized solar cells, it is still inferior to the rising perovskite cells and much lower than its own 44% theoretical conversion efficiency Further improving the utilization efficiency of sunlight is the fundamental way to prepare qdsc with high photoelectric conversion efficiency, and it is also the technical bottleneck for the development of such batteries Source: in order to solve this problem, the school of chemistry and molecular engineering of East China University of science and technology, for the first time, studied the preparation of multi-component quantum dot co sensitized photoanode and qdsc assembly by surface ligand induced self-assembly loading in TiO 2 porous membrane Based on the wide spectrum absorption (~ 1100 nm) of Zn Cu in SE quantum dots and the high molar extinction coefficient (> 105 cm-1) of CdSe in the visible region, the co sensitized qdsc not only improves the absorption efficiency of solar photons, but also realizes the effective separation of photogenerated electrons Combined with mesoporous carbon loaded titanium mesh pair electrode and polysulfide electrolyte, the assembled qdsc with sandwich structure finally achieved 12.75% photoelectric conversion efficiency, refreshing the photoelectric conversion efficiency record of similar batteries The synergistic effect of different quantum dots is used to improve the conversion and utilization of sunlight, which provides a new idea for the preparation of efficient quantum dot batteries Source: the research group of School of chemistry and molecular engineering of East China University of science and technology has been committed to the research of qdsc in recent years In the aspect of photoanode, PBS / CdS core-shell quantum dots were synthesized by ion exchange method, which significantly reduced the defect density of state on PBS surface, and improved the photoelectric conversion efficiency of liquid connected qdsc based on PbS quantum dots from 5.7% to 7.19% (J mater Chem A 2016, 4, 7214); in the aspect of counter electrode, Co / N Co doped porous carbon is prepared by carbonizing the metal organic framework material with Zn / CO bimetallic zeolite imidazole framework structure The application of this kind of carbon material ensures the effective diffusion of polysulfide electrolyte in the prepared counter electrode and the efficient transfer of charge between the interfaces, so it shows good catalytic activity in the corresponding reduction process (J mater Chem A 2018, DOI:10.1039/C7TA09976B); in order to solve the problem that QDSC is difficult to encapsulate and leak easily, a polyelectrolyte with high water absorbency and strong water shrinkage is used to gelate the polysulfide electrolyte and build a quasi solid state QDSC, which improves the stability without reducing the photoelectric conversion efficiency of the battery （ J Mater Chem A 2016 , 4 , 1461； J Mater Chem A 2016 , 4 , 14894； J Mater Chem A 2015 , 3 , 17097； Res Chem Intermed 2018, DOI 10.1007/s11164-017-3159-1）。 Paper link: http://onlinelibrary.wiley.com/doi/10.1002/adma.201705746/abstract profile of Associate Professor Li Yan: http://chem.security.edu.cn/2014/1209/c6655a50458/page.htm profile of Associate Professor Zhong Xinhua: http://chem.security.edu.cn/2014/1113/c6655a50105/page.htm profile of Associate Professor Zhong Xinhua