講演情報
[19p-P04-28]The role of plasma treatment of FTO substrate in enhancing the Jsc of tin perovskite solar cells
〇Liu Jiaqi1, Liang Wang1, Qing Shen1, Shuzi Hayase1 (1.UEC)
キーワード：
perovskite
The various cleaning procedures have been identified to be critical for the efficiency of perovskite solar cells3). The cleaning procedures usually provide the hydroxyls on the TCO surface. We found that the pressure of plasma cleaning of the FTO substrate strongly affected the perovskite solar cell's current density (1 mA/cm2 increment (Figure 1b)). The various pressures (0.1 mbar, 0.3 mbar, and 0.5 mbar) of air plasma were designed to understand the mechanism of this phenomenon. Firstly, the water contact angle on the plasma-treated FTO was measured. The FTO surface possessed better hydrophilicity under a plasma pressure of 0.1 mbar. Meanwhile, the quantity of the hydroxyl was detected by XPS. Thus, we can conclude that the various quantity of hydroxyl contributes to the difference in hydrophilicity. The contact AFM technique was used to measure the current vs. voltage curve. The IV curves imply the various resistance under various plasma pressures, which suggests the thickness of the PEDOT:PSS layer was affected by the treatment of FTO. The optical property was examined to clarify the reason for the increased current density, and there was no distinct difference between the samples under various plasma treatments. Therefore, the reason should be attributed to the carrier transport. Then, the TRPL was used to investigate the carrier dynamics on the device structure of FTO/PEDOT:PSS/Perovskite. The carrier lifetime was longer in the sample under 0.5 mbar (32 ns) than 0.1 mbar (13 ns) (Figure 1a), reflecting the difference in carrier transport. The crystal quality must be considered because the bottom layer was different. XRD analysis shows no distinct difference in the crystal quality of perovskite, which means the plasma treatment pressure does not affect the growth of perovskite films. As a result, the plasma treatment dramatically modified the property of the PEDOT:PSS layer, thus being a significant step for high-efficiency solar cells.