Liu Yanping, Xia Qinglin, He Jun, Liu Zongwen
Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, 932 South Lushan Road, Changsha, Hunan, 410083, People's Republic of China.
Department of Materials Science and Engineering, University of California, Berkeley, California, 94720, USA.
Nanoscale Res Lett. 2017 Dec;12(1):93. doi: 10.1186/s11671-017-1827-0. Epub 2017 Feb 7.
Ultrafast and broad spectral bandwidth photodetectors are desirable attributable to their unique bandstructures. Photodetectors based on graphene have great potential due to graphene's outstanding optical and electrical properties. However, the highest reported values of the photoresponsivity of pure graphene are less than 10 mA/W at room temperature, which significantly limits its potential applications. Here, we report a photoresponsivity of 32 A/W in pure monolayer graphene photodetectors, an improvement of over one order of magnitude for functional graphene nanostructures (<3 A/W). The high photocurrent generation in our devices can be attributed to the high sensitivity of graphene's resistivity to a local change of the electric field induced by photo-excited carriers generated in the light-doping substrate. This dramatically increases the feasibility of using graphene for the next generation of photodetectors.
超快且具有宽带光谱带宽的光电探测器因其独特的能带结构而备受青睐。基于石墨烯的光电探测器由于石墨烯出色的光学和电学特性而具有巨大潜力。然而，据报道，纯石墨烯在室温下的光响应度最高值小于10 mA/W，这极大地限制了其潜在应用。在此，我们报道了纯单层石墨烯光电探测器的光响应度为32 A/W，相较于功能性石墨烯纳米结构（<3 A/W）提高了一个多数量级。我们器件中产生的高光电流可归因于石墨烯的电阻率对由光掺杂衬底中光激发载流子产生的局部电场变化的高灵敏度。这显著提高了将石墨烯用于下一代光电探测器的可行性。
