Fabrication and hard X-ray photoemission analysis of photocathodes with sharp solar-blind sensitivity using AlGaN films grown on Si substrates
Fabrication and hard X-ray photoemission analysis of photocathodes with sharp solar-blind sensitivity using AlGaN films grown on Si substrates
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DOI：
10.1016/j.apsusc.2010.01.038
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发表时间：
2010-05-01
影响因子：
6.7
通讯作者：
Fuke, Shunro
中科院分区：
文献类型：
--
作者：
Sumiya, Masatomo;Kamo, Yutaro;Fuke, Shunro
利用生长在Si（111）衬底上的p-AlxGa 1-xN薄膜，研制了工作在反射模式下的深紫外光电阴极器件。在200 nm和280 nm处，外量子效率高达20-15%，而在310 nm处，外量子效率仅为10 ~（-2）%。开关比超过四个数量级，这代表了高的日盲灵敏度。AlxGa 1-xN光电阴极的逃逸几率随AlN摩尔分数的增加而降低。由于AlxGa_（1-x）N的导带上移，表面附近的有效势垒降低。从AlxGa 1-xN薄膜终止与Cs-O吸附原子的光电子发射将被讨论的硬X射线光电子能谱评估的能带图。(C)2010 Elsevier B. V.保留所有权利。
Photocathode devices operating in reflection-mode, where the photoemission is detected on the same side as the light irradiation, were developed for the detection of deep ultraviolet light by using p-AlxGa1-xN films grown on Si(111) substrates. The external quantum efficiencies were as high as 20-15% at 200 nm and 280 nm, while the value was as low as 10(-2)% at 310 nm. The on-off ratio was more than four orders of magnitude, which represents high solar-blind sensitivity. The escape probability of AlxGa1-xN photocathode was decreased with increase of AlN mole fraction. The effective barrier potential against the photoelectron emission near the surface was reduced due to the upward shift of conduction band of AlxGa1-xN. The photoemission from the AlxGa1-xN films terminated with Cs-O adatoms will be discussed in terms of band diagrams that were evaluated by hard X-ray photoelectron spectroscopy. (C) 2010 Elsevier B.V. All rights reserved.