Singh Ningthoujam Somorjit, Mia Abdul Kaium, Giri P K
Centre for Nanotechnology, Indian Institute of Technology Guwahati Guwahati 781039 India
Department of Physics, Indian Institute of Technology Guwahati Guwahati 781039 India.
Nanoscale Adv. 2024 Mar 15;6(8):2136-2148. doi: 10.1039/d3na01120h. eCollection 2024 Apr 16.
Integrating low-dimensional graphene oxide (GO) with conventional Si technology offers innovative strategies for developing ultrafast wideband photodetectors. In this study, we synthesized GO and explored its potential application in broadband photodetection alongside silicon heterostructures. The as-synthesized GO contains various oxygen functional groups, as evidenced by X-ray photoelectron and Fourier transform infrared spectroscopy. These functional groups contribute to increased photo absorption, enhancing photodetection performance. The systematic reduction of these functional groups from the GO surface thermal annealing decreases photo absorption and consequently lowers the photocurrent. This reduction diminishes photo absorption and amplifies the dark current by approximately 25 times, from 20 nA to 496 nA. This dark current increase is attributed to the electron mobility following the reduction of functional groups. However, attaching plasmonic gold nanoparticles (Au NPs) to the GO surface enhances UV-Vis absorption in the visible region, enabling broadband detection. The even distribution of attached Au NPs on the GO surface is confirmed through field emission transmission electron microscopy. While thermal annealing of GO diminishes the responsivity from 4.6 A W to 3.0 A W, the attachment of Au NPs augments the responsivity by more than two-fold, reaching 10.0 A W. Thus, it highlights the importance of rich oxygen functional groups in GO and the attachment of Au NPs to achieve more efficient photo-sensing properties.
将低维氧化石墨烯（GO）与传统硅技术相结合，为开发超快宽带光电探测器提供了创新策略。在本研究中，我们合成了GO，并探索了其在宽带光电探测以及硅异质结构中的潜在应用。合成的GO含有各种氧官能团，X射线光电子能谱和傅里叶变换红外光谱证明了这一点。这些官能团有助于增加光吸收，提高光电探测性能。通过热退火系统地减少GO表面的这些官能团会降低光吸收，从而降低光电流。这种减少会减少光吸收，并使暗电流放大约25倍，从20 nA增加到496 nA。这种暗电流增加归因于官能团减少后的电子迁移率。然而，在GO表面附着等离子体金纳米颗粒（Au NPs）可增强可见光区域的紫外-可见吸收，实现宽带探测。通过场发射透射电子显微镜证实了附着的Au NPs在GO表面的均匀分布。虽然GO的热退火使响应度从4.6 A/W降至3.0 A/W，但Au NPs的附着使响应度提高了两倍多，达到10.0 A/W。因此，这突出了GO中丰富的氧官能团以及Au NPs的附着对于实现更高效光传感特性的重要性。
