Kunwar Sundar, Pandit Sanchaya, Kulkarni Rakesh, Mandavkar Rutuja, Lin Shusen, Li Ming-Yu, Lee Jihoon
Department of Electronic Engineering, College of Electronics and Information, Kwangwoon University, Nowon-gu Seoul 01897, South Korea.
School of Science, Wuhan University of Technology, Wuhan, Hubei 430070, China.
ACS Appl Mater Interfaces. 2021 Jan 20;13(2):3408-3418. doi: 10.1021/acsami.0c19058. Epub 2021 Jan 5.
In this work, a nanoscale device architecture is demonstrated for a UV photodetector application on sapphire (0001), incorporating the plasmonic hybrid nanoparticles (HNPs), graphene quantum dots (GQDs), and titanium oxide (TiO) for the first time. The hybrid GQDs/TiO/HNPs photodetector exhibits the photocurrent of 1.58 × 10 A under the 1.64 mW/mm of 275 nm illumination at 10 V, which is around two order increase from the bare TiO device. The proposed architecture demonstrates a low dark current of ∼1 × 10 A at 10 V and thus the device demonstrates an excellent photo to dark current ratio along with the improved rise and fall time on the order of several hundred millisecond. The enhanced performance of device architecture is attributed to the efficient utilization of localized surface plasmon resonance (LSPR) induced hot carriers as well as scattered photons from the plasmonic HNPs that are fully encapsulated by the photoactive TiO layers. Furthermore, the addition of GQDs on the TiO can offer an additional photon absorption pathway. The proposed hybrid architecture of GQDs/TiO/HNPs demonstrates the integration of the photon absorption and carrier transfer properties of plasmonic HNPs, GQDs, and TiO for an enhanced ultraviolet (UV) photoresponse. The photocurrent enhancement mechanisms of the hybrid device architecture are thoroughly investigated based on the finite-difference time domain (FDTD) simulation along with the energy band analysis. This work demonstrates a great potential of the hybrid device architecture for high-performance UV photodetectors.
在这项工作中，首次展示了一种用于蓝宝石（0001）上紫外光电探测器应用的纳米级器件架构，该架构集成了等离子体混合纳米颗粒（HNP）、石墨烯量子点（GQD）和氧化钛（TiO）。混合GQD/TiO/HNP光电探测器在10 V电压下，275 nm光照强度为1.64 mW/mm时，光电流为1.58×10 A，比裸TiO器件增加了约两个数量级。所提出的架构在10 V电压下显示出约1×10 A的低暗电流，因此该器件具有出色的光暗电流比，同时上升和下降时间缩短至几百毫秒量级。器件架构性能的提升归因于对局部表面等离子体共振（LSPR）诱导的热载流子以及来自被光活性TiO层完全包裹的等离子体HNP散射光子的有效利用。此外，在TiO上添加GQD可以提供额外的光子吸收途径。所提出的GQD/TiO/HNP混合架构展示了等离子体HNP、GQD和TiO的光子吸收和载流子转移特性的整合，以增强紫外（UV）光响应。基于时域有限差分（FDTD）模拟和能带分析，深入研究了混合器件架构的光电流增强机制。这项工作展示了混合器件架构在高性能紫外光电探测器方面的巨大潜力。
