Summary: | 碩士 === 國立中興大學 === 化學系所 === 105 === The tremendous consuming of fossil fuel to the human community has lead to energy crisis and drawn people’s attention to the environmental issue as well as the searching for alternative energy resources. Solar energy is a powerful and fascinating energy resource for the viewpoint of either research or development. Based on this, perovskite solar cells(PSCs)has recently become one of the fascinating solar energy-harvesting technologies which drives us to study.
This thesis focuses on the design and synthesis of porphyrin-based hole-transporting materials (HTMs) for the applications in PSCs. We have synthesized dimeric porphyrin WT3 which is based on high-efficiency monomeric porphyrin Y2 recently devised by our group. Both HTMs has the D-π-D type molecular structure. Compare to Y2, WT3 has broader UV-vis absorption, stabilized HOMO and porphyrin moiety bearing good hole-transporting ability. This advantages are believed to benefit both the open-circuit voltage (VOC) and short-circuit current (JSC) of the corresponding PSC devices. As a result, WT3 has high power conversion efficiency of 19.4%, outperforms that based on Y2 of 17.9% or Spiro-OMeTAD.
We have also synthesized a series of D-π-A type porphyrin HTMs WT4 ~ WT9, where donor (D) represents substituted dialkylaniline donor and acceptor (A) represents either the methyl benzoate or dicyanovinyl groups.
Due to the functionalization of electron-accepting groups, these series of HTMs feature lowered LUMO level and narrower bandgap. Interestingly, HTMs WT4 ~ WT6 have PCE of 13.4 ~ 16.5% thank to suitable HOMO levels. Unfortunately, HTMs WT7 ~ WT9 have poorer performance with PCE are less than 8 % possibly owing to too low of the corresponding HOMO levels. In conclusion, the perfect matching of HOMO levels for HTMs with that for perovskite is very important.
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