An Efficient Nanophotonic Hot Electron Solar-Blind UV Detector
An Efficient Nanophotonic Hot Electron Solar-Blind UV Detector
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DOI：
10.1021/acsphotonics.8b01055
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发表时间：
2018-09
期刊：
影响因子：
7
通讯作者：
Zhiyuan Wang;Xiaoxin Wang;Jifeng Liu
中科院分区：
文献类型：
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作者：
Zhiyuan Wang;Xiaoxin Wang;Jifeng Liu
基于纳米光子金属氧化物半导体结构设计和制造了日盲紫外光电探测器。金属/氧化物界面处约 3.8 eV 的大势垒通过阻挡可见光子激发的电子同时允许紫外线激发的热电子通过，从而实现日盲紫外线检测。通过选择费米能级附近具有高态密度的金属吸收剂，并在自组装赝周期金属纳米结构中采用光子管理，我们成功地在 λ = 200–300 nm 处实现了约 74% 的光谱平均紫外吸收。此外，如此高的紫外线吸收是在距金属/氧化物界面约50 nm的热电子平均自由程内实现的，有效促进了紫外线激发的热电子穿过界面势垒的弹道传输，并提高了整体光电流。该器件的响应度为 29 mA/W，在 λ = 269 nm 时内量子效率为 ∼18%，与 ∼1% 的内量子效率相比，这是一个显着的进步。
A solar-blind UV photodetector is designed and fabricated based on a nanophotonic metal–oxide–semiconductor structure. A large potential barrier of ∼3.8 eV at the metal/oxide interface enables solar-blind UV detection by blocking the electrons excited by visible photons while allowing UV-excited hot electrons to pass through. By selecting metal absorbers with high density of states near the Fermi level and employing photon management in self-assembled pseudoperiodic metal nanostructures, we managed to achieve ∼74% spectrally averaged UV absorption at λ = 200–300 nm. Furthermore, such a high UV absorption is achieved within the hot electron mean free path of ∼50 nm from the metal/oxide interface, effectively facilitating the ballistic transport of the UV-excited hot electrons across the interfacial barrier and improving the overall photocurrent. The device has demonstrated a responsivity of 29 mA/W and an internal quantum efficiency of ∼18% at λ = 269 nm, a significant advance compared to ∼1% internal quan...