Center for Nanophysics and Advanced Materials and Materials Research Science and Engineering Center, University of Maryland, College Park, MD 20742, USA.
Nat Nanotechnol. 2012 Jun 3;7(7):472-8. doi: 10.1038/nnano.2012.88.
Graphene is an attractive material for use in optical detectors because it absorbs light from mid-infrared to ultraviolet wavelengths with nearly equal strength. Graphene is particularly well suited for bolometers-devices that detect temperature-induced changes in electrical conductivity caused by the absorption of light-because its small electron heat capacity and weak electron-phonon coupling lead to large light-induced changes in electron temperature. Here, we demonstrate a hot-electron bolometer made of bilayer graphene that is dual-gated to create a tunable bandgap and electron-temperature-dependent conductivity. The bolometer exhibits a noise-equivalent power (33 fW Hz(-1/2) at 5 K) that is several times lower, and intrinsic speed (>1 GHz at 10 K) three to five orders of magnitude higher than commercial silicon bolometers and superconducting transition-edge sensors at similar temperatures.
石墨烯是一种有吸引力的材料，可用于光学探测器，因为它对从中红外到紫外波长的光的吸收率几乎相等。石墨烯特别适合用于测辐射热计——一种通过检测光吸收引起的电导率温度变化来探测温度的器件，因为其小的电子热容和弱的电子-声子耦合导致电子温度发生大的光致变化。在这里，我们展示了一个由双层石墨烯制成的热电子测辐射热计，该测辐射热计采用双栅极结构来创建可调带隙和与电子温度相关的电导率。该测辐射热计的噪声等效功率（在 5 K 时为 33 fW Hz−1/2）低几个数量级，固有速度（在 10 K 时>1 GHz）比类似温度下的商用硅测辐射热计和超导相变边缘传感器高三到五个数量级。
