Quantitative Evaluation of Electron Injection Efficiency in Dye-Sensitized TiO2 Films
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The efficiency of electron injection (Φinj) in dye-sensitized nanocrystalline films was studied through transient absorption (TA) and time-resolved microwave conductivity (TRMC) measurements. Here, I show the absolute value of Φinj for several dye-sensitized nanocrystalline films and discuss the relationship between Φinj and the free energy change (−ΔG inj) for the injection process. Some systems exhibited lower Φinj values even when −ΔG inj was sufficiently large to promote electron injection. Recent experimental findings are used to propose possible explanations for this phenomenon. Quantitative evaluation of Φinj using TA and TRMC will give us new insights for developing high-performance solar cell devices.
KeywordsDye-sensitized solar cells Transient absorption spectroscopy Time-resolved microwave conductivity Electron injection efficiency Free energy change
This study was supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan.
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