Abstract BaTiO3 is used to fabricate the electron transport layer of perovskite solar cells due to its spontaneous polarization. Li+ ions were doped into BaTiO3 by the hydrothermal synthesis to increase the spontaneous polarization. The particle size of the as-prepared BaTiO3 nanoparticles becomes smaller and more uniform for doping of Li+ ions with a molar ratio of 1.0 during the synthesis processes. The absorption edge shifts towards the short wavelength with the increase in the doping amount. Further, TiO2 nanocrystalline thin film was deposited on the Li-doped BaTiO3 thin film, the double layer was used as an electron transport layer of perovskite solar cell to indirectly demonstrate the effect of doping on the spontaneous polarization of BaTiO3. The perovskite solar cell based on BaTiO3 with 1.0 doping molar ratio of Li+ ions shows the highest light-to-electric conversion efficiency of 14.3% accompanying with the highest short-circuit photocurrent density. The measurements of impedance spectra and intensity modulating photocurrent spectra indicate that the photocurrent enhancement of perovskite solar cells is attributed to the spontaneous polarization enhancement of Li-doped BaTiO3 thin films. The enhanced internal electric field in the BaTiO3 thin layer accelerates the photogenerated electron transport in the electron transport layer of perovskite solar cell.

中文翻译：

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由于 Li+ 掺杂的 BaTiO3 自发极化钙钛矿太阳能电池的电子传输增强

摘要 BaTiO3 具有自发极化特性，可用于制备钙钛矿太阳能电池的电子传输层。通过水热合成将 Li+ 离子掺杂到 BaTiO3 中以增加自发极化。在合成过程中，对于以 1.0 的摩尔比掺杂 Li+ 离子，所制备的 BaTiO3 纳米粒子的粒径变得更小且更均匀。随着掺杂量的增加，吸收边向短波长移动。此外，在掺锂的BaTiO3薄膜上沉积TiO2纳米晶薄膜，将双层用作钙钛矿太阳能电池的电子传输层，间接证明了掺杂对BaTiO3自发极化的影响。基于 BaTiO3 的钙钛矿太阳能电池具有 1. Li+离子掺杂摩尔比为0时，光电转换效率最高，为14.3%，短路光电流密度最高。阻抗谱和强度调制光电流谱的测量表明钙钛矿太阳能电池的光电流增强归因于掺锂 BaTiO3 薄膜的自发极化增强。BaTiO3 薄层中增强的内部电场加速了钙钛矿太阳能电池电子传输层中的光生电子传输。阻抗谱和强度调制光电流谱的测量表明钙钛矿太阳能电池的光电流增强归因于掺锂 BaTiO3 薄膜的自发极化增强。BaTiO3 薄层中增强的内部电场加速了钙钛矿太阳能电池电子传输层中的光生电子传输。阻抗谱和强度调制光电流谱的测量表明钙钛矿太阳能电池的光电流增强归因于掺锂 BaTiO3 薄膜的自发极化增强。BaTiO3 薄层中增强的内部电场加速了钙钛矿太阳能电池电子传输层中的光生电子传输。