High sensitivity ultraviolet detection based on three-dimensional graphene field effect transistors decorated with TiO₂ NPs

Abstract

Three-dimensional graphene FETs decorated with TiO2 nanoparticles are used as high-sensitivity ultraviolet photodetectors with tunable responsivity and response time.

Trap-Assisted Charge Storage in Titania Nanocrystals toward Optoelectronic Nonvolatile Memory

“…The N-TiO 2 device and the control device demonstrate an apparent difference in this regard. After the light was off, the excited I DS of the control device decayed to the initial level in about 120 s. Thus, the control device behaves like a typical photodetector as reported before. ,− Besides, it is worth noting that the commercial TiO 2 NCs have a shape different from that of the N-TiO 2 NCs. To exclude the impact of the shape on the device performance, N-doping TiO 2 nanorods (N-TiO 2 NRs) were synthesized using the same recipe as the N-TiO 2 NCs except for different reaction temperature and duration (see the Supporting Information).…”

“…Hence, the photogating effect can persist for a long time. Notice that this is very different from the previous reports on the phototransistors based on the hybrid of TiO 2 NCs and graphene, in which the photocurrents saturated swiftly under light illumination and decayed fast to zero after the excitation light was off. ,− To make a direct comparison, commercial TiO 2 NCs with a rod shape and dimension of ∼5–25 nm were purchased to fabricate a control device with the identical device structure. The TEM images of the commercial TiO 2 NCs are shown in Figure S3a,b.…”

“…Although NCs of carbon, perovskites, CdSe, CdSe/ZnS core–shell, etc. , have been applied in optoelectronic memories, a number of semiconductors with excellent properties have yet to be investigated. In this regard, titania (TiO 2 ) is worthy of exploration considering its visible-blind ultraviolet (UV) optoelectronic property and successful application in photocatalysis, solar cells, photodetector, etc. − Integrating TiO 2 NCs into transistors has brought forth UV photodetectors with diverse features. − However, optoelectronic transistor-based memory taking advantage of the UV harnessing ability of TiO 2 NCs has been rarely studied. Here, we report an optoelectronic memory based on a graphene transistor decorated with TiO 2 NCs that was prepared using a facile solution method at low temperature.…”

A graphene‐metamaterial hybrid structure for the design of reconfigurable low pass terahertz filters

“…Finally, the device was put in heat oven for 10 minutes at 50°C to anneal. As shown in Figure 2B,D, the clear edge of the transferred graphene and the Raman spectroscopy indicate the success of the transfer process 24 …”

Mechanism, Material, Design, and Implementation Principle of Two-Dimensional Material Photodetectors

“…Deng et al fabricated self-rolled-up 3D graphene field-effect transistor (GFET) photodetectors (Figure 11c), which have shown for the first time a balance among the optical responsivity, spectral range, and bandwidth [107]. The self-rolled-up 3D GFETs provide a naturally resonant microcavity that enhances the optical field and increases the area of the light-graphene interaction, thus significantly enhancing the light absorption (Figure 11e) [108]. The optical responsivity of the 3D GFETs is significantly improved.…”