Rutile TiO2-based perovskite solar cells
Rutile TiO2-based perovskite solar cells
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DOI：
10.1039/c4ta01786b
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发表时间：
2014-01-01
影响因子：
11.9
通讯作者：
Park, Nam-Gyu
中科院分区：
文献类型：
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作者：
Lee, Jin-Wook;Lee, Taek-Yong;Park, Nam-Gyu
制备了一种基于金红石型TiO 2薄膜的钙钛矿太阳能电池，并将其光伏性能与金红石型TiO 2基钙钛矿太阳能电池进行了比较。采用室温水解法制备了长径比为0.2（宽20 nm，长100 nm）的金红石型TiO 2纳米粒子。水热法合成了粒径约为50 nm的锐钛矿型TiO 2纳米粒子。退火的金红石膜显示出60.6%的孔隙率，而较低的孔隙率为49.1%，检测到的TiO 2薄膜。采用一步旋涂法和两步浸渍法在TiO 2薄膜上制备了CH 3 NH3 PbI 3钙钛矿薄膜。使用2，2 '，7，7'-四（N，N-对-二甲氧基-苯基氨基）-9，9 '-螺二芴（螺-MeO 2）作为空穴传输材料。一步沉积导致金红石-钙钛矿太阳能电池的平均功率转换效率（PCE）为8.19%，锐钛矿-钙钛矿太阳能电池为7.23%，而两步沉积导致前者的平均PCE为13.75%，后者为13.99%。无论沉积方法如何，金红石-钙钛矿太阳能电池通常显示出较高的J（sc）和较低的V-oc。慢的电子传输和较长的电子寿命观察到的金红石型钙钛矿太阳能电池比锐钛矿型的。虽然相同的钙钛矿材料用于金红石型和金红石型TiO 2，但电子行为的差异表明，光激发电子部分注入TiO 2，电子注入的程度可能受到TiO 2晶相的影响。尽管电子寿命较长，但金红石基器件的电压略低可能是由于金红石的注入电子量相对大于金红石，导致TiO 2和钙钛矿之间平衡时的费米能级较低。在260 nm厚的金红石型TiO 2薄膜上，采用两步法沉积CH_3NH_3PbI_3，光电流密度为20.02 mA·cm ~（-2），开路电压为1.022 V，填充因子为0.71，光电转换效率达到14.46%。
A perovskite solar cell based on rutile TiO2 film was prepared and its photovoltaic performance was compared to an anatase TiO2-based perovskite solar cell. Rutile TiO2 nanoparticles with aspect ratio of 0.2 (20 nm wide and 100 nm long) were prepared by hydrolysis of TiCl4 at ambient temperature. Anatase TiO2 nanoparticles with diameter of about 50 nm were hydrothermally synthesized. The annealed rutile film showed porosity of 60.6%, while lower porosity of 49.1% was detected in the anatase TiO2 film. CH3NH3PbI3 perovskite was deposited on TiO2 film using either a one-step spin coating or two-step dipping method. 2,2',7,7'-Tetrakis(N,N-p-dimethoxy-phenylamino)-9,9'-spirobifluorene (spiro-MeOTAD) was used as a hole transporting material. One-step deposition led to average power conversion efficiency (PCE) of 8.19% from the rutile-perovskite solar cells and 7.23% from the anatase-perovskite solar cells, while two-step deposition resulted in higher average PCE of 13.75% for the former device and 13.99% for the latter one. Regardless of the deposition methodologies, the rutile-perovskite solar cell showed generally higher J(sc) and lower V-oc. Slower electron transport and longer electron lifetime were observed for the rutile-based perovskite solar cell than for the anatase-based one. Although the same perovskite material was used for both rutile and anatase TiO2, the difference in electronic behavior indicates that photo-excited electrons are in part injected to TiO2 and the extent of electron injection can be influenced by the crystal phase of TiO2. Despite longer electron lifetime, the slightly lower voltage of the rutile-based device might be due to the fact that the amount of injected electrons was relatively larger for rutile than anatase, leading to a lower Fermi energy level at equilibrium between TiO2 and perovskite. Using a 260 nm-thick rutile TiO2 film, the highest PCE of 14.46% was achieved by depositing CH3NH3PbI3 using a two-step method, in which photocurrent density of 20.02 mA cm(-2), open-circuit voltage of 1.022 V and fill factor of 0.71 were demonstrated.