It is extremely significant to study the trap state passivation and minimize the trap states of perovskite to achieve high-performance perovskite solar cells (PSCs). Here, we have first revealed and demonstrated that a novel p-type conductor Cu(thiourea)I [Cu(Tu)I] incorporated in perovskite layer can effectively passivate the trap states of perovskite via interacting with the under-coordinated metal cations and halide anions at the perovskite crystal surface. The trap state energy level of perovskite can be shallowed from 0.35–0.45 eV to 0.25–0.35 eV. In addition, the incorporated Cu(Tu)I can participate in constructing the p–i bulk heterojunctions with perovskite, leading to an increase of the depletion width from 126 to 265 nm, which is advantageous for accelerating hole transport and reducing charge carrier recombination. For these two synergistic effects, Cu(Tu)I can play a much better role than that of the traditional p-type conductor CuI, probably due to its identical valence band maximum with that of perovskite, which enables to not only lower the trap state energy level to a greater extent but also eliminate the potential wells for holes at the p–i heterojunctions. After optimization, a breakthrough efficiency of 19.9% has been obtained in the inverted PSCs with Cu(Tu)I as the trap state passivator of perovskite.

中文翻译：

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通过使用有效的陷阱态钝化剂Cu（thiourea）I，在反向钙钛矿太阳能电池中获得了19.9％的突破效率。

研究陷阱态钝化并最小化钙钛矿的陷阱态以实现高性能钙钛矿太阳能电池（PSC）极为重要。在这里，我们首先揭示并证明，掺入钙钛矿层中的新型p型导体Cu（硫脲）I [Cu（Tu）I]可以通过与配位不足的金属阳离子和卤化物相互作用而有效地钝化钙钛矿的陷阱态。钙钛矿晶体表面的阴离子。钙钛矿的陷阱态能级可以从0.35–0.45 eV降低到0.25–0.35 eV。此外，掺入的Cu（Tu）I可以参与使用钙钛矿构造p–i本体异质结，从而导致耗尽层宽度从126 nm增加到265 nm，这对于加速空穴传输和减少电荷载流子的重组是有利的。对于这两种协同作用，Cu（Tu）I可以比传统的p型导体CuI发挥更好的作用，这可能是由于其最大价带与钙钛矿的价带相同，这不仅降低了陷阱能级能级更大程度地消除了p–i异质结处空穴的势阱。经过优化，以Cu（Tu）I作为钙钛矿的陷阱态钝化剂，在反相PSC中获得了19.9％的突破效率。