Iodomethane-Mediated Organometal Halide Perovskite with Record Photoluminescence Lifetime
Iodomethane-Mediated Organometal Halide Perovskite with Record Photoluminescence Lifetime
复制标题
碘甲烷介导的有机金属卤化物钙钛矿具有创纪录的光致发光寿命
DOI：
10.1021/acsami.6b05770
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发表时间：
2016
影响因子：
9.5
通讯作者：
Sun Baoquan
中科院分区：
文献类型：
--
作者：
Xu Weidong;McLeod John A.;Yang Yingguo;Wang Yimeng;Wu Zhongwei;Bai Sai;Yuan Zhongcheng;Song Tao;Wang Yusheng;Si Junjie;Wang Rongbin;Gao Xingyu;Zhang Xinping;Liu Lijia;Sun Baoquan
有机金属卤化铅钙钛矿是高效光电器件的优秀光收集器。然而，作为这些器件的关键部件，具有良好形态和最小陷阱态的钙钛矿薄膜仍然难以获得。本研究表明，通过在前驱体溶液中加入低沸点的烷基卤化物如碘甲烷（CH3I），可以很容易地获得具有改善晶粒尺寸和取向的钙钛矿（CH3NH3PbI3-xClx）薄膜。更重要的是，这些薄膜表现出显著减少的陷阱态。实现了超过4 μs的创纪录光致发光寿命；这些寿命明显长于原始ch3nh3pbi3 - xclx薄膜。与使用原始CH3NH3PbI3-xClx的太阳能电池相比，使用这些ch3i介导的钙钛矿的平面异质结太阳能电池显示出显着提高的功率转换效率。光致发光、瞬态吸收和微波检测光电导率测量都提供了一致的证据，表明CH3I的加入增加了激子的数量和扩散长度，这两者都有助于光电器件中有效的载流子传输。烷基卤化物的简单掺入增强钙钛矿表面钝化，为未来高效钙钛矿光电器件的发展指明了重要方向。
Organometallic lead halide perovskites are excellent light harvesters for high-efficiency photovoltaic devices. However, as the key component in these devices, a perovskite thin film with good morphology and minimal trap states is still difficult to obtain. Herein we show that by incorporating a low boiling point alkyl halide such as iodomethane (CH3I) into the precursor solution, a perovskite (CH3NH3PbI3–xClx) film with improved grain size and orientation can be easily achieved. More importantly, these films exhibit a significantly reduced amount of trap states. Record photoluminescence lifetimes of more than 4 μs are achieved; these lifetimes are significantly longer than that of pristine CH3NH3PbI3–xClxfilms. Planar heterojunction solar cells incorporating these CH3I-mediated perovskites have demonstrated a dramatically increased power conversion efficiency compared to the ones using pristine CH3NH3PbI3–xClx. Photoluminescence, transient absorption, and microwave detected photoconductivity measurements all provide consistent evidence that CH3I addition increases the number of excitons generated and their diffusion length, both of which assist efficient carrier transport in the photovoltaic device. The simple incorporation of alkyl halide to enhance perovskite surface passivation introduces an important direction for future progress on high efficiency perovskite optoelectronic devices.