Effects of graphene quantum dots interlayer on performance of ZnO-based photodetectors

Mousavi, Seyedeh Soraya; Kazempour, Ali; Efafi, Babak; Ara, M.H. Majles; Sajad, Batool

doi:10.1016/j.apsusc.2019.07.145

Cited by 18 publications

(15 citation statements)

References 37 publications

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“…With the addition of GQDs, the energy band alignment can be seen in Figure h according to its work function (2.9 eV) and band gap (∼2.5 eV) . The thin GQD layer can act as additional light absorbers to effectively enhance the carrier concentration in the ZnO conductive channel via the carrier injection due to its high carrier mobility . This can lead to high conductivity and increased I ph in the GQD/ZnO/AHNP PD as can be evaluated by the following equation, σ = italicne μ = ( n 0 + d d 0 V T n ) e μ , where σ is conductivity, μ is the electron mobility, and n 0 is the intrinsic electron density of ZnO.…”

Section: Resultsmentioning

confidence: 99%

Hybrid UV Photodetector Design Incorporating AuPt Alloy Hybrid Nanoparticles, ZnO Quantum Dots, and Graphene Quantum Dots

Lin

Habib

Burse

et al. 2022

ACS Appl. Mater. Interfaces

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A hybrid device scheme is an attractive strategy in the construction of advanced UV photodetectors due to the flexibility in selecting the components and correspondingly improved optoelectronic properties by the cooperation of various components, which cannot be achieved by a single component device. In this work, a novel hybrid UV photodetector (PD) is demonstrated by adapting AuPt alloy hybrid nanoparticles (AHNPs), ZnO quantum dots (QDs), and graphene quantum dots (GQDs), namely, GQD/ZnO/AHNP PD. The optimized device achieves high-end figure-of-merit performance with a responsivity of 2299 mA/W, detectivity of 7.04 × 10 10 jones, and external quantum efficiency of 741%. Enhanced photocurrent can be associated with the hot electron generation around the AuPt AHNPs and swift transfer to the conduction band of ZnO QDs. At the same time, the added carrier injection is achieved by a thin layer of GQDs. High density of hotspots and electromagnetic fields are generated by the strong localized surface plasmon resonance (LSPR) by the uniquely designed AuPt AHNPs with the fully alloyed AuPt NPs and adjacent small background Au NPs. The e-field distribution of various NP configurations is systematically investigated with finite-difference time-domain (FDTD) simulations.

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Section: Resultsmentioning

confidence: 99%

Hybrid UV Photodetector Design Incorporating AuPt Alloy Hybrid Nanoparticles, ZnO Quantum Dots, and Graphene Quantum Dots

Lin

Habib

Burse

et al. 2022

ACS Appl. Mater. Interfaces

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“…The emitted light is detectable in PL spectroscopy. 37 Factors affecting the formation of PL peaks in the graphene nanostructures include dimensions and sizes of thin sheets, the existence of oxygenated functional groups, and the presence of sp 3 carbon bonds in the nanostructures. The oxygen present in the ethanol molecule can lead to insignificant oxidation of the graphene structure, followed by forming oxygenated functional groups on the nanostructured edges and engendering small energy traps in the triangular sheet structure (Figure 12).…”

Section: Resultsmentioning

confidence: 99%

“…The PL spectra of the samples are shown in Figure . We have studied PL of some materials in recent research. − From this research, we can determine energy levels and band gaps in the structures of the samples using the PL spectrum. Decreasing the area of graphene sheets disrupts the integrity and interference of π orbital electrons in the system and the emergence of quantum limitation effects that gives rise to particular optical properties depending on the size of the sheets.…”

Section: Resultsmentioning

confidence: 99%

“…Eventually, the electrons return to their original state by emitting light of a wavelength different from that of the excitation light. The emitted light is detectable in PL spectroscopy . Factors affecting the formation of PL peaks in the graphene nanostructures include dimensions and sizes of thin sheets, the existence of oxygenated functional groups, and the presence of sp 3 carbon bonds in the nanostructures.…”

Section: Resultsmentioning

confidence: 99%

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Preparing a New Class of Ultrathin Graphene Nanostructure by Chemical Vapor Deposition and Its Lasing Ability

Tehrani

Efafi

Ara

2020

ACS Appl. Mater. Interfaces

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In this paper, we report a new method to grow graphene monolayers directly on a quartz substrate using chemical vapor deposition (CVD), without using any catalyst. For this purpose, ethanol as the precursor and a quartz substrate were used for growth, which controlled the growth process and the formation of an ultrathin layer of graphene. In this project, with use of plasmaenhanced chemical vapor deposition (PECVD), the substrate was cleaned by applying the cold plasma with the aim of improving the quality of the graphene monolayer grown. Atomic force microscopy (AFM) and Raman spectroscopy confirm that the graphene layer in regular triangular pieces grew to 200 nm in size. Photoluminescence spectroscopy (PL) of the samples showed a sharp peak in the blue spectrum, which indicates lasing emission in the graphene nanostructure. Finally, at a lower cost than other CVD methods, we have formed an ultrathin graphene layer on a dielectric substrate that can have many applications in the laser and photonics fields.

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“…The optical detectors are one of the most important components in wearable electronic devices for measuring light in various applications [1]. Semiconductor materials with wide-bandgap such as ZnO, SiC, GaN, and TiO2 have been used for producing Ultraviolet (UV) PDs and solar cells [2][3][4][5][6][7][8][9][10]. Among them, ZnO has attracted researchers' attention due to its unique features, including cheapness, high chemical stability, strong radiation hardness, high charge carrier mobility, and most importantly, the 3.37 eV wide-bandgap [3,6,[11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Electrode Shape on Schottky Barrier and Electric Field Distribution of Flexible ZnO Photodiode

Jezeh

Efafi

Ghafary

2021

Preprint

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Three metal-semiconductor-metal (MSM) ultraviolet flexible self-powered photodiode (PDs) were fabricated, which differed in the shape of the electrodes. Here, the effect of the electrode's shape on the height of the Schottky barrier and the electric field in these PDs was investigated. They were prepared based on porous Zinc Oxide (ZnO) on fiberglass. Different shapes of the electrodes affect the height of the Schottky barrier in each metal-semiconductor contact and provide the basis for the formation of self-powered PDs. It also affects the electric field generated in the PD's bias condition and affects the PD's parameter. They were fabricated using the radio frequency (RF) sputtering technique, and copper electrodes with different shapes and a sample with interdigitated electrodes were created using the printed circuit board (PCB) method. The photocurrent of the sample with circular and rectangular electrodes was equal to 470 μA in 15V bias, which was twice as good as a sample with an interdigitated MSM structure. It also had the best photocurrent at 0V, which is equal to 0.8 μA. This sample had the best response time among these three samples, which was equal to 440 ms. It is noteworthy that the simulation data confirmed the practical results.

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Effects of graphene quantum dots interlayer on performance of ZnO-based photodetectors

Cited by 18 publications

References 37 publications

Hybrid UV Photodetector Design Incorporating AuPt Alloy Hybrid Nanoparticles, ZnO Quantum Dots, and Graphene Quantum Dots

Hybrid UV Photodetector Design Incorporating AuPt Alloy Hybrid Nanoparticles, ZnO Quantum Dots, and Graphene Quantum Dots

Preparing a New Class of Ultrathin Graphene Nanostructure by Chemical Vapor Deposition and Its Lasing Ability

The Effect of Electrode Shape on Schottky Barrier and Electric Field Distribution of Flexible ZnO Photodiode

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