Hybrid graphene/silicon Schottky photodiode with intrinsic gating effect
Hybrid graphene/silicon Schottky photodiode with intrinsic gating effect
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DOI：
10.1088/2053-1583/aa6aa0
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发表时间：
2017-06-01
期刊：
影响因子：
5.5
通讯作者：
Lupina, Grzegorz
中科院分区：
文献类型：
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作者：
Di Bartolomeo, Antonio;Luongo, Giuseppe;Lupina, Grzegorz
我们提出了一种由石墨烯/硅（Gr/Si）肖特基二极管与Gr/SiO2/Si电容器并联组成的混合器件，用于高性能光电检测。该器件通过在低掺杂n型Si衬底上转移商业石墨烯而制成，在可见光范围内实现了高达3AW（-1）的光响应和高于3.5 × 10（1/2）cm Hz（1/2）W-1的归一化探测率。它表现出超过正向电流的光电流，因为光生的少数载流子，积累在Gr/SiO2/Si电容器的Si/SiO2界面，扩散到Gr/Si结。我们表明，同样的机制，当由于热产生的载流子，虽然通常被忽视或忽视，导致增加泄漏经常测量Gr/Si异质结。我们在不同温度下进行了广泛的I-V和C-V特性测试，并在室温下测量了0.52 eV的零偏压肖特基势垒高度，以及有效Richardson常数A** = 4 × 10（-5）Acm（-2）K（-2）和理想因子n约为3.6，这是由Gr/Si界面处的薄（< 1 nm）氧化层解释的。
We propose a hybrid device consisting of a graphene/silicon (Gr/Si) Schottky diode in parallel with a Gr/SiO2/Si capacitor for high-performance photodetection. The device, fabricated by transfer of commercial graphene on low-doped n-type Si substrate, achieves a photoresponse as high as 3 AW(-1) and a normalized detectivity higher than 3.5x10(12) cm Hz(1/2) W-1 in the visible range. It exhibits a photocurrent exceeding the forward current because photo-generated minority carriers, accumulated at Si/SiO2 interface of the Gr/SiO2/Si capacitor, diffuse to the Gr/Si junction. We show that the same mechanism, when due to thermally generated carriers, although usually neglected or disregarded, causes the increased leakage often measured in Gr/Si heterojunctions. We perform extensive I-V and C-V characterization at different temperatures and we measure a zero-bias Schottky barrier height of 0.52 eV at room temperature, as well as an effective Richardson constant A** = 4x10(-5)Acm(-2)K(-2) and an ideality factor n approximate to 3.6, explained by a thin (< 1 nm) oxide layer at the Gr/Si interface.