AI 中文总结
研究探索大面积CVD石墨烯用于光电探测，利用衬底诱导光闸效应产生光电导信号，通过测量证明光闸效应主导作用，单层石墨烯灵敏度最高，其灵敏度受层数和制造路线影响，展现了CVD石墨烯在光电探测器上的潜力。
AI 中文摘要
我们的工作探索了大面积化学气相沉积（CVD）石墨烯作为光电探测器的可扩展平台。我们表明，石墨烯/SiO₂/Si结构中的衬底诱导光闸效应能在单层、双层和三层CVD石墨烯中产生光电导信号。这些器件对高于硅带隙的光子能量的光照有响应，对电信频率无响应，表明是通过光闸效应产生光电导机制。通过大面积样品和与栅极电压相关的电阻率测量，我们直接证明了光闸效应的主导作用，展示了电容再充电电流和光响应的相似性。单层石墨烯的灵敏度最高（995 A/W）。增加石墨烯层数会因屏蔽和平行传导而降低灵敏度，但可通过降低噪声水平提高探测率。CVD石墨烯器件的灵敏度取决于光刻制造路线：在石墨烯转移前制造金属接触的器件具有更高的光响应。因此，我们的工作证明了工业相关的CVD石墨烯在基于灵敏光闸的光电探测器方面的潜力。
英文摘要
Our work explores large-area CVD graphene as a scalable platform for photodetectors. We show that substrate-induced photogating in graphene/SiO$_2$/Si structures enables a photoconductivity signal in mono-, bi-, and trilayer CVD graphene. The devices respond to illumination with photon energies above the Si band gap and do not respond to telecom frequency, suggesting the photoconductivity mechanism through the photogating. Large sample area and gate voltage-dependent resistivity measurements allow us to prove the dominant role of the photogating directly, demonstrating similarity of the capacitive recharging current and the photoresponse. The sensitivity is the highest (995 A/W) for the monolayer graphene. Increasing the number of graphene layers reduces the sensitivity due to screening and parallel conduction, but can improve detectivity by lowering the noise level. The sensitivity of CVD graphene device depends on fabrication route of photolitography: device with metal contacts fabricated before graphene transfer show higher photoresponce. Thus, our work demonstrate the potential of industrially relevant CVD graphene for sensitive photogating-based photodetectors.
Comments6 pages, 4 figures
