Unveiling the Role of the Metal Oxide/Sn Perovskite Interface Leading to Low Efficiency of Sn-Perovskite Solar Cells but Providing High Thermoelectric Properties
Unveiling the Role of the Metal Oxide/Sn Perovskite Interface Leading to Low Efficiency of Sn-Perovskite Solar Cells but Providing High Thermoelectric Properties
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DOI：
10.1021/acsaem.2c01437
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发表时间：
2022-08-10
影响因子：
6.4
通讯作者：
Hayase, Shuzi
中科院分区：
文献类型：
--
作者：
Baranwal, Ajay Kumar;Saini, Shrikant;Hayase, Shuzi
卤化锡钙钛矿(THPS)具有与卤化铅钙钛矿(LHPS)相似的光电性质。然而，在普通结构的钙钛矿型太阳电池中，涂覆在金属氧化物电极上的THPS二极管整流能力较差，导致效率较低。N-i-p基THP太阳电池的这种较差的光电性能与LHP太阳电池形成鲜明对比。我们报道，THP太阳电池的这种性能缺陷是由金属氧化层的缺陷态触发的。金属氧化物的缺陷态可以俘获THP中的电子，导致锡(IV)的迅速形成，从而增加载流子密度，导致光电性能变差。这一观察结果得到了无机薄膜Al_2O_3、SnO_2、TiO_2、ZnO和ZrO_2的紫外光电子能谱测量的支持。然而，这种导致载流子密度增加的自掺杂现象可以应用于热电研究。报道了用CsSnI_3/ZrO(2)纳米复合材料作为热电有源层，在室温下测得的功率因数为186.58 mU W/mK(2)，优于原来的CsSnI_3薄膜的148.61 mU W/mK(2)。
Tin halide perovskites (THPs) have appealing optoelectronic properties similar to lead halide perovskites (LHPs). However, THPs coated on metal oxide electrodes in normal-structure perovskite solar cells exhibit poor diode rectification, resulting in poor efficiency. This poor photoelectric performance in n-i-p-based THP solar cells is in contrast with LHP solar cells. We report that this deficient performance of THP solar cells is triggered by the defect states of the metal oxide layer. The defect states of the metal oxide can trap the electrons from the THP, leading to the prompt formation of Sn(IV), which will increase the carrier density and lead to poor photoelectric performance. This observation was supported by the ultraviolet-photoelectron spectroscopic measurements of inorganic thin films Al2O3, SnO2, TiO2, ZnO, and ZrO2. However, this self-doping phenomenon resulting in the increase in carrier density can be applied to thermoelectric studies. Using CsSnI3/ZrO(2 )nanocomposites as thermoelectric active layers, we report a power factor of 186.58 mu W/mK(2) measured at room temperature, which is better than the 148.61 mu W/mK(2 )of the original CsSnI3 thin film.