钙钛矿太阳能电池中TiO_2纳米棒电子传输层的制备及光电性能研究

近年来,有机—无机杂化钙钛矿由于合适禁带宽度、高吸光系数及长载流子扩散长度成为当前太阳能电池的研究热点。其中,电子传输层对电子传输及电子—空穴对的分离效果起着至关重要的作用。普遍认为,介孔结构的TiO_2纳米棒电子传输层可以有效地增加电子传输层及其与钙钛矿光吸收层的接触面积,加快电子传输速率,降低电子—空穴对的复合几率,从而可以显著提升光电转换效率。采用水热法在FTO玻璃上原位合成金红石相TiO_2纳米棒,系统地研究不同水热反应时间对TiO_2纳米棒的长度及致密度的影响规律,并探索其对太阳能电池光电性能的影响规律。采用TiO_2纳米棒作为电子传输层组装介孔钙钛矿太阳能电池,其最佳光电转换效率达到10.36%。

Preparation and Photovoltaic Performance of Perovskite Solar Cells using TiO_2 Nanorod as Electron Transporting Layer

In recent years, organic-inorganic hybrid perovskites have become the research hotspot of solar cells due to their suitable band gap, high absorption coefficient and long charge carrier diffusion length. The electron transport layer of perovskite solar cells plays an important role in the electrons transport and the separation of electron-hole pairs. The electron transport layer of the TiO2 nanorod with mesoporous structure can effectively increase the contact area of electron transport layer and perovskite layer, and hence favor for the transport of electrons and reduce the recombination of electrons and holes to improve the photoelectric conversion efficiency. Rutile TiO2 nanorod was in-situ prepared on the FTO glass by a hydrothermal method. The influence of the reaction time on the length and density of TiO2 nanorod were investigated, and the effect on the photovoltaic efficiency of solar cells was further demonstrated. Eventually,the mesoporous perovskite solar cells could obtain the open-circuit voltage of 921 mV, shortcircuit current density of 17.12 mA/cm^2, fill factor of 0.657 and photovoltaic efficiency of 10.36%.