Maximizing the optical performance of planar CH3NH3PbI3 hybrid perovskite heterojunction stacks
Maximizing the optical performance of planar CH3NH3PbI3 hybrid perovskite heterojunction stacks
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DOI：
10.1016/j.solmat.2015.10.007
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发表时间：
2016-04-01
影响因子：
6.9
通讯作者：
Durose, Ken
中科院分区：
文献类型：
--
作者：
Phillips, Laurie J.;Rashed, Atef M.;Durose, Ken
用气相反应法制备了光滑均匀的CH3NH3PbI3钙钛矿材料，用椭偏仪测量了其光学色散关系n和k。用Tauc-Lorenz、临界点抛物带(CPPB)和简谐振子相结合的方法进行拟合。我们在新的平面器件结构的全光学模型中使用了色散关系，以便为未来的材料选择建立设计规则，以最大化短路电流(J(Sc))性能。对于没有窗口层的500 nm MAPI，模型所期望的最大性能为J(Sc)=21.63 mA cm(-2)。研究了一系列窗口层材料(二氧化钛、WO_3、氧化锌、Nb_2O_5、硫化镉和Cd-0.4Zn0.6S)的薄层(在20-60 nm范围内)增强器件短路电流的能力。氧化物的性能表现出干扰行为，其J(Sc)曲线的第一极大值超过了在没有窗口层的情况下可以达到的值。然而，在第一个最大值之后，性能一般随着厚度的增加而下降。在整个研究范围内保持大于无窗口条件的唯一材料是WO_3。当WO_3为59 nm时，性能最好(J(Sc)为22.47 mA·cm~(-2))，其次是二氧化钛、氧化锌和Nb_2O_5。CDS窗口层中的寄生吸收导致所有非零厚度的J(Sc)降低-它没有提供干涉增强，因此不能基于光学原因推荐使用它。使用宽禁带合金Cd_(0.4)Zn_(0.6)S比使用Cd_s有较大的电流，但其性能不如氧化物。在实际光伏器件的制作中，观察了制作靶结构的实用性。(C)2015年提交人。由Elsevier B.V.出版。这是CC许可下的一篇开放获取文章。
A vapour-phase reaction process has been used to deposit smooth and uniform CH3NH3PbI3 perovskite material to enable the measurement of its optical dispersion relations, n and k, by ellipsometry. Fitting was achieved with a combination of Tauc-Lorenz, critical point parabolic band (CPPB) and harmonic oscillators. We have used the dispersion relations in an all-optical model of new planar device architectures in order to establish design rules for future materials choices to maximize the short-circuit current (J(sc)) performance. For 500 nm of MAPI with no window layer, the maximum performance expected from the model is J(sc) = 21.63 mA cm(-2). The ability of thin layers (in the range 20-60 nm) of a range of window layer materials (TiO2, WO3, ZnO, Nb2O5, CdS, and Cd-0.4 Zn0.6S) to enhance the short-circuit current of the devices was investigated. The performance of the oxides showed interference behaviour, with the first maxima in their J(sc) curves exceeding the value achievable without a window layer. However, after the first maximum, the performance generally fell off with increasing thickness. The only material to stay greater than the no-window condition for the entire investigated range is WO3. The highest performance (J(sc) of 22.47 mA cm(-2)) was obtained with 59 nm of WO3, with that of TiO2, ZnO, and Nb2O5 being marginally lower. Parasitic absorption in CdS window layers caused the J(sc) to decrease for all non -zero thicknesses - it gives no interference enhancement and its use cannot be recommended on optical grounds. Use of the wider gap alloy Cd0.4Zn0.6S gave higher currents than did CdS but its performance was not so high as for the oxides. Observations are made on the practicalities of fabricating the target structures in the fabrication of practical PV devices. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.