College of Microelectronics, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China.
Nanoscale. 2018 May 3;10(17):8023-8030. doi: 10.1039/c8nr00594j.
Near-infrared photodetectors (NIRPDs) have attracted great attention because of their wide range of applications in many fields. Herein, a novel self-driven NIRPD at the wavelength of 980 nm is reported based on the graphene/GaAs heterostructure. Extraordinarily, its sensitivity to light illumination (980 nm) is far beyond the absorption limitation of GaAs (874 nm). This means that the photocurrent originates from the separation of photo-induced carriers in graphene, which is caused by the vertically built-in electric field formed through the high quality van der Waals contact between graphene and GaAs. Moreover, after introducing NaYF4:Yb3+/Er3+ upconversion nanoparticles (UCNPs) onto the graphene/GaAs heterojunction, the responsivity increases to be as superior as 5.97 mA W-1 and the corresponding detectivity is 1.1 × 1011 cm Hz0.5 W-1 under self-driven conditions. This dramatic improvement is mainly ascribed to the radiative energy transfer from UCNPs to the graphene/GaAs heterostructure. The high-quality and self-driven UCNPs/graphene/GaAs heterostructure NIRPD holds significant potential for practical application in low-consumption and large-scale optoelectronic devices.
近红外光电探测器 (NIRPD) 因其在许多领域的广泛应用而受到极大关注。在此，我们报道了一种基于石墨烯/砷化镓异质结的新型自驱动 980nm 近红外光电探测器。值得注意的是，其对光照明 (980nm) 的灵敏度远远超出了砷化镓 (874nm) 的吸收限制。这意味着光电流源于石墨烯中光致载流子的分离，这是由石墨烯和砷化镓之间高质量的范德华接触形成的垂直内置电场引起的。此外，在石墨烯/砷化镓异质结上引入 NaYF4:Yb3+/Er3+ 上转换纳米粒子 (UCNPs) 后，在自驱动条件下，响应率提高到 5.97 mA W-1，相应的探测率高达 1.1×1011 cm Hz0.5 W-1。这种显著的改善主要归因于 UCNPs 到石墨烯/砷化镓异质结构的辐射能量转移。这种高质量的自驱动 UCNPs/石墨烯/砷化镓异质结构近红外光电探测器在低功耗、大规模光电器件的实际应用中具有重要的应用潜力。
