論文標題：Ultrafast zero-bias photocurrent and terahertz emission in hybrid perovskites
期刊：Communications Physics
作者：Petr A. Obraztsov, Dmitry Lyashenko, Pavel A. Chizhov, Kuniaki Konishi, Natsuki Nemoto, Makoto Kuwata-Gonokami, Eric Welch, Alexander N. Obraztsov & Alex Zakhidov
發表時間：2018/04/19
數字識別碼：10.1038/s42005-018-0013-8
原文連結：https://www.nature.com/articles/s42005-018-0013-8?utm_source=Other_website&utm_medium=Website_links&utm_content=RenLi-Nature-Communications_Physics-Materials_Physics-China&utm_campaign=NEWCOMMS_USG_rlp8212_perovskite_sciencenet_article_June_4th
本周《通訊-物理學》發表的一項研究Ultrafast zero-bias photocurrent and terahertz emission in hybrid perovskites展示了在室溫條件下，甲基碘化鉛胺中超快光電流的產生以及自由空間太赫茲的發射。
甲基碘化鉛胺是一種標準的可用於低成本印刷太陽能電池的雜化有機鈣鈦礦材料，其功率轉化效率高於20%。然而，目前關於在雜化鈣鈦礦中的光與物質相互作用的本質，以及潛藏在器件操作過程中的確切物理機制仍存有爭論。
來自俄羅斯普羅霍羅夫物理研究所和東芬蘭大學的Petr A. Obraztsov，美國德克薩斯州立大學的Dmitry Lyashenko和日本東京大學的Kuniaki Konishi及其同事，他們報導了由飛秒光脈衝在無偏壓的雜化鈣鈦礦中誘導的室溫超快光電流的產生，以及自由空間太赫茲的發射。他們觀察到的光響應的極化依賴與注入和轉移電流相結合所產生的體光伏效應一致。對這種類型光電流的觀測可以揭示出由CH3NH3PbI3的間接帶隙所引起的較低的重組和較長的載流子擴散長度。自然的彈道移位和注入的光電流可以使第三代鈣鈦礦太陽能電池的效率超過肖克利——奎伊瑟效率極限。通過光偏振對光電流的控制也可為鈣鈦礦自旋電子學和可控太赫茲器件開闢新的途徑。
摘要：Methylammonium lead iodide is a benchmark hybrid organic perovskite material used for low-cost printed solar cells with a power conversion efficiency of over 20%. Nevertheless, the nature of light–matter interaction in hybrid perovskites and the exact physical mechanism underlying device operation are currently debated. Here, we report room temperature, ultrafast photocurrent generation, and free-space terahertz emission from unbiased hybrid perovskites induced by femtosecond light pulses. The polarization dependence of the observed photoresponse is consistent with the bulk photovoltaic effect caused by a combination of injection and shift currents. Observation of this type of photocurrents sheds light on the low recombination and long carrier diffusion lengths arising from the indirect bandgap in CH3NH3PbI3. Naturally ballistic shift and injection photocurrents may enable third-generation perovskite solar cells with efficiency exceeding the Shockley–Queisser limit. The demonstrated control over photocurrents with light polarization also opens new venues toward perovskite spintronics and tunable THz devices.
閱讀論文全文，請訪問：https://www.nature.com/articles/s42005-018-0013-8?utm_source=Other_website&utm_medium=Website_links&utm_content=RenLi-Nature-Communications_Physics-Materials_Physics-China&utm_campaign=NEWCOMMS_USG_rlp8212_perovskite_sciencenet_article_June_4th
期刊介紹：Communications Physics is an open access journal from Nature Research publishing high-quality research, reviews and commentary in all areas of physics. Research papers published by the journal represent significant advances bringing new insight to a specialized area of research.
Communications Physics complements the other Nature Research journals by providing a new open access option for physicists while applying less stringent criteria for impact and significance than the Nature-branded journals, including Nature Communications. All Nature Research journals, including Communications Physics, apply the same criteria for technical validity and adherence to ethical standards.（來源：科學網）
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