15:30 〜 15:45
▼ [15p-A401-9] Dual TiO2 Electron Transport Layers Formed by Magnetron Sputtering and Spin Coating Methods for Planar Perovskite Solar Cells
キーワード：perovskite solar cell, TiO2 based electron transport layer, dual electron transport layer structure
Electron transport layers (ETLs) play a vital role for perovskite solar cells (PSCs). Uniform and pin-hole free ETLs are essential for achieving the high efficiency of PSCs. In this research, we have combined both spin-coating and magnetron sputtering deposition techniques to form dual ETLs. The spin-coating method was conducted by our original single-crystalline TiO2 nanoparticles. The sputtering method was done by TiO2 targets and argon/hydrogen gas mixtures. The structure of PSCs is shown in fig.1.
Figure 2 and table 1 show the current-voltage (J-V) characteristics in reverse voltage scans and the photovoltaic characteristics, respectively, of the PSCs. It was observed that the PSC having dual ETL showed significant improvement especially in the reverse scans in the photovoltaic characteristics compared with the PSC without the sputtered ETL. This is because the sputtered layer effectively compensates the ununiform formation of the spin-coated layer and reduces the electrons-holes recombination at the interface between ETLs and photovoltaic layers. The effect of argon/hydrogen gas ratios in magnetron sputtering was also studied. Three different argon/hydrogen gas ratios were tested and compared in fig.2 and table 1. It can be seen that the gas mixture of 88% Ar and 12% H2 showed the best performance among the others. The inclusion of hydrogen atoms increases the conductivity of sputtered TiO2 probably due to causing oxygen vacancies, which resulted in improved carrier transportation reflected by the increased the short circuit current (Jsc) and the open circuit voltage (Voc). Thus, this research demonstrated the importance of the dual ETL with the sputtered layer with hydrogen and the spin-coated layer of single-crystalline TiO2 nanoparticles.
Figure 2 and table 1 show the current-voltage (J-V) characteristics in reverse voltage scans and the photovoltaic characteristics, respectively, of the PSCs. It was observed that the PSC having dual ETL showed significant improvement especially in the reverse scans in the photovoltaic characteristics compared with the PSC without the sputtered ETL. This is because the sputtered layer effectively compensates the ununiform formation of the spin-coated layer and reduces the electrons-holes recombination at the interface between ETLs and photovoltaic layers. The effect of argon/hydrogen gas ratios in magnetron sputtering was also studied. Three different argon/hydrogen gas ratios were tested and compared in fig.2 and table 1. It can be seen that the gas mixture of 88% Ar and 12% H2 showed the best performance among the others. The inclusion of hydrogen atoms increases the conductivity of sputtered TiO2 probably due to causing oxygen vacancies, which resulted in improved carrier transportation reflected by the increased the short circuit current (Jsc) and the open circuit voltage (Voc). Thus, this research demonstrated the importance of the dual ETL with the sputtered layer with hydrogen and the spin-coated layer of single-crystalline TiO2 nanoparticles.