一种基于AlGaN和石墨烯的紫外-红外双色探测器

通过MOCVD和CVD生长技术,利用高Al组分Al Ga N和单层石墨烯材料进行纵向集成,成功制备了日盲紫外-近红外双色探测器。在工作温度为室温、调制频率为209 Hz以及工作电压分别为10 V和5 V的工作条件下,所制备的双色探测器在紫外波段263 nm处的响应度为5.9 m A/W,在近红外波段1.15μm处的响应度为0.67 m A/W,并且探测器的响应度均随着工作电压的增加而增大。     

高温退火Cu(111)衬底上生长高质量厘米尺寸单晶石墨烯（英文）

二维(2D)石墨烯具有原子层厚度，在电子器件中展示出突破摩尔定律限制的巨大潜力。目前，化学气相沉积(CVD)是一种广泛应用于石墨烯生长的方法，满足低成本、大面积生产和易于控制层数的需求。然而，由于催化金属(例如Cu)衬底一般为多晶特性，导致CVD法生长的石墨烯晶体质量相对较差。为此，通过高温退火工艺制备了Cu (111)单晶衬底，使石墨烯的初始成核过程得到了很好的控制，从而实现了厘米尺寸的高质量单晶石墨烯的制备。根据二者的晶格匹配关系，Cu (111)衬底为石墨烯生长提供了唯一的成核取向，相邻石墨烯成核岛的边界能够缝合到一起。单晶石墨烯具有高电导率，相较于原始多晶Cu上生长的石墨烯(1 415.7Ω·sq^-1),其平均薄层电阻低至607.5Ω·sq^-1。高温退火能够清洁铜箔，从而获得表面粗糙度较低的洁净石墨烯。将石墨烯用于场效应晶体管(FET),器件的最大开关比为145.5,载流子迁移率为2.31×10³ cm²·V^-1·s^-1。基于以上结果，相信本工作中...     

Highly responsive broadband black phosphorus photodetectors

Black phosphorus(BP) is a promising material for ultrafast and broadband photodetection because of its narrow bandgap from 0.35 eV(bulk) to 1.8 eV(monolayer) and high carrier mobility. Although photodetectors based on BP with different configurations have been reported, high photosensitivity was mostly observed in the visible range. A highly efficient BP-based infrared photodetector operated in the telecom spectral range, especially at 1550 nm, has not been demonstrated. Here, we report a Schottky-type photodetector based on thin BP flakes,operating in a broad spectral range from visible(635 nm) to infrared(1550 nm). A responsivity as high as 230 A·W~(-1) was achieved at 1550 nm with a source-drain bias of 1 V. The rise time is 4.8 ms, and the fall time is 6.8 ms. Under light illumination and external bias, the Schottky barrier between the BP and metal was reduced, leading to efficient photocurrent extraction. The unprecedented performance of the BP photodetector indicates intriguing potential for sensing, imaging, and optical communication.