Ultrafast Triplet Generation at the Lead Halide Perovskite/Rubrene Interface
Ultrafast Triplet Generation at the Lead Halide Perovskite/Rubrene Interface
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DOI：
10.1021/acsenergylett.1c02732
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发表时间：
2022-01-12
影响因子：
22
通讯作者：
Nienhaus, Lea
中科院分区：
文献类型：
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作者：
Conti, Carl R., III;Bieber, Alexander S.;Nienhaus, Lea
最近，通过大块卤化铅钙钛矿对红荧烯的三重态敏化导致了通过三重态-三重态湮灭的有效的红外到可见光光子上转换。值得注意的是，这一过程可以在太阳能相关通量下发生，可能为与光伏器件集成铺平道路。为了进一步提高上转换效率，必须清楚地理解钙钛矿/红荧烯界面处的基本物理路径以最大化电荷提取。在这里，我们利用超快瞬态吸收光谱来阐明在钙钛矿/红荧烯界面的三重态生成的过程。我们的研究结果指出了一个三重态产生机制的基础上热载流子的钙钛矿中的热激发的电荷载流子冷却更迅速的红荧烯的存在下，这表明这些热激发载流子的皮秒时间尺度上的快速提取。随后的三重态形成红荧烯观察到的时间尺度为亚纳秒。
Triplet sensitization of rubrene by bulk lead halide perovskites has recently resulted in efficient infrared-to-visible photon upconversion via triplet-triplet annihilation. Notably, this process can occur under solar relevant fluxes, potentially paving the way toward integration with photovoltaic devices. In order to further improve the upconversion efficiency, the fundamental photophysical pathways at the perovskite/rubrene interface must be clearly understood to maximize charge extraction. Here, we utilize ultrafast transient absorption spectroscopy to elucidate the processes underlying triplet generation at the perovskite/rubrene interface. Our results point to a triplet generation mechanism based on hot carriers; thermally excited charge carriers in the perovskite cool more rapidly in the presence of rubrene, suggesting rapid extraction of these thermally excited carriers on the picosecond time scale. Subsequent triplet formation in rubrene is observed on a subnanosecond time scale.