图 6  (a) PTIR显微镜下MAPbI3薄膜在1.6 V/μm电场极化100和200 s前后, MA+离子的分布图, 其中电极间距为100 μm[43]; (b)实验中用XPS方法于测试元素分布的横向器件和实验装置示意图及测得的从阳极到阴极之间的I/Pb比例分布图(c), 施加的直流电压为1 V, 持续时间30 min, 两电极间的横向距离为200 μm, 其中位置“0”为接近正极处, 位置“8”为接近阴极处[70]; (d)横向器件中具有PbI2条形区域的SEM和XRD分析, 对横向结构的MAPbI3薄膜电场极化后具有典型的PbI2条形区域的SEM图(d)和极化前后的XRD图(e); (f), (h)EDX测试下的具有PbI2条形区域的横向钙钛矿器件的碘元素(f)和铅元素(h)分布图; (g), (i) 分别为碘元素和铅元素在(f), (h) 白线处的浓度变化曲线[35]

Fig. 6.  (a) Corresponding PTIR images for the CH3 asymmetric deformation absorption of the methylammonium ion (1468 cm–1) obtained before, after 100 s and after 200 s electrical poling, respectively. The poling field was 1.6 V/µm and the distance between the electrode is 100 μm[43]. (b) Illustration of the set-up for characterization of elements distribution using a lateral structure with XPS method and the obtained I/Pb ration against position from anode side to cathode side (c). The applied DC voltage is 1 V for 30 min. The lateral distance between two electrodes is 200 µm. Position 0 is near the anode and position 8 is near cathode side[70]. (d) SEM and XRD study of the lateral devices with a PbI2 thread. By electric polarization of MAPbI3 films with lateral symmetric electrode structure, SEM image (d) of a typical PbI2 thread, (e) XRD spectra of the MAPbI3 film before and after the formation of a PbI2 thread. (f), (h) The distribution diagram of iodine (f) and lead element (h) of lateral perovskite device with PbI2 thread line under energy dispersion X-ray (EDX) test. (g), (i) The concentration curves of iodine (g) and lead (i) at the white line in Figs. (f) and (h), respectively[35].