Near full light absorption and full charge collection in 1-micron thick quantum dot photodetector using intercalated graphene monolayer electrodes
Near full light absorption and full charge collection in 1-micron thick quantum dot photodetector using intercalated graphene monolayer electrodes
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DOI：
10.1039/c9nr09901h
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发表时间：
2020-02-28
期刊：
影响因子：
6.7
通讯作者：
Vazquez-Mena, Oscar
中科院分区：
文献类型：
--
作者：
Chen, Wenjun;Ahn, Seungbae;Vazquez-Mena, Oscar
量子点在光电子学中具有许多优点，例如易于溶液处理、强光吸收和尺寸可调的直接带隙。然而，它们的主要限制是它们差的膜迁移率和短的扩散长度（在QD光电探测器和光伏器件中为700 nm），导致降低的光响应性和对太阳光谱的近红外部分的差的吸收。在这里，我们展示了1 μ m厚的量子点光电探测器与嵌入式石墨烯电荷收集器，避免了量子效率的显着下降，对λ> 700 nm观察到在大多数量子点光电器件。1 μ m厚的插层QD膜确保了强的光吸收，同时使用插层石墨烯层作为电荷收集器，在100 nm的间距下，从λ = 600 nm至950 nm保持有效的电荷提取，量子效率为90%-70%。我们证明了石墨烯对光吸收的影响是最小的。我们实现了时间调制响应，
Quantum dots (QDs) offer several advantages in optoelectronics such as easy solution processing, strong light absorption and size tunable direct bandgap. However, their major limitation is their poor film mobility and short diffusion length ( 700 nm in QDs photodetector and photovoltaic devices, causing a reduced photoresponsivity and a poor absorption towards the near-infrared part of the sunlight spectrum. Herein, we demonstrate 1 mu m thick QDs photodetectors with intercalated graphene charge collectors that avoid the significant drop of quantum efficiency towards lambda > 700 nm observed in most QD optoelectronic devices. The 1 mu m thick intercalated QD films ensure strong light absorption while keeping efficient charge extraction with a quantum efficiency of 90%-70% from lambda = 600 nm to 950 nm using intercalated graphene layers as charge collectors with interspacing distance of 100 nm. We demonstrate that the effect of graphene on light absorption is minimal. We achieve a time-modulation response of