High-performance solar-blind flexible deep-UV photodetectors based on quantum dots synthesized by femtosecond-laser ablation

Mitra, Somak; Aravindh, Assa; Das, Gobind; Pak, Yusin; Ajia, Idris A.; Loganathan, Kalaivanan; Fabrizio, Enzo M. Di; Roqan, Iman S.

doi:10.1016/j.nanoen.2018.03.077

Cited by 79 publications

(89 citation statements)

References 48 publications

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“…The effect of charge in formation energy is not estimated, as no charged defects were included in these calculations. Our findings indicate that V Zn forms more easily relative to the V O , which is also indicated by the results obtained in previous studies pertaining to same-sized clusters [19].…”

Section: Stability and Energetics Of The Clustersupporting

confidence: 90%

“…In this cluster, the coordination number of each atom is 3, and the atomic rings consist of 4 and 6 atoms. The uniqueness of this cluster geometry stems from all the atoms being located on the surface, which is effectively equivalent to ZnO nanoparticle or QD structures synthesized experimentally [19]. The Zn-O bond length in the optimized cluster is 1.83 Å , whereas in bulk wurtzite ZnO, the Zn-O bond length is 1.99 Å .…”

Section: Stability and Energetics Of The Clustermentioning

confidence: 89%

“…It is possible to successfully stabilize the defects and dopants in this cluster geometry [10], because the pristine ZnO nanoparticles are not suitable for practical applications due to uncontrollable defects [19]. The optimized cluster structure is shown in Fig.…”

Section: Stability and Energetics Of The Clustermentioning

confidence: 99%

“…Among the RE atoms, Eu is of special interest, as Eu-doped wide band gap semiconductors exhibit many potential optoelectronic applications because of the partially filled Eu 4f states that introduce remarkable optical characteristics [16][17][18]. Eu can be easily incorporated into the cation sites in ZnO nanoparticles [16,19]. Eu-doped ZnO nanocrystals possessing high crystallinity that have been prepared by nano emulsion method exhibited changes in magnetic properties with concentration [20].…”

Section: Introductionmentioning

confidence: 99%

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Density Functional Theory Studies of Zn12O12 Clusters Doped with Mg/Eu and Defect Complexes

2020

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We report a density functional theory study of ZnO cluster doped with Eu and Mg along with native point defects using the generalized gradient approximation including the Hubbard parameter. The Zn atomic positions are found to be energetically more favorable doping sites than O. The Eu has a lower formation energy than Zn and O vacancies, helps in lowering the formation energy of point defects and induces spin polarization. Mg is less favorable dopant energetically and is not inducing any magnetism in the cluster. Presence of Eu and point defects along with Mg can help in sustaining spin polarization, implying that transition metal and rare earth dopant is a favorable combination to invoke desirable properties in ZnO based materials. Eu-Eu doping pair prefers ferromagnetic orientation and a spin flip is induced by Eu in the Eu-Mg configuration. Further, Eu doping increases the value of static refractive index and optical absorption in the UV region compared to the undoped ZnO cluster.

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Section: Stability and Energetics Of The Clustersupporting

confidence: 90%

Section: Stability and Energetics Of The Clustermentioning

confidence: 89%

Section: Stability and Energetics Of The Clustermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Density Functional Theory Studies of Zn12O12 Clusters Doped with Mg/Eu and Defect Complexes

2020

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“…Ultraviolet (UV) detection technique has developed a wide potential range of applications in both civilian and military fields, such as environmental monitoring, flame sensing, and space exploration . UV photodetectors show many excellent properties including intrinsically less interference from the visible region, high radiation hardness, and filter free . Owing to relatively high saturated carrier drift rate, large exciton energy (60 meV), and wide direct bandgap, ZnO has drawn abundant research interests as an alternative candidate for the fabrication of high‐performance UV photodetectors.…”

Section: Introductionmentioning

confidence: 99%

Ultrahigh Responsivity UV Photodetector Based on Cu Nanostructure/ZnO QD Hybrid Architectures

et al. 2019

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Strong near‐surface electromagnetic field formed by collective oscillation of electrons on Cu nanostructure a shows a strong dependence on geometry, offering a promising approach to boost the light absorption of ZnO photoactive layers with enhanced plasmon scattering. Here, a facile way to fabricate UV photodetectors with tunable configuration of the self‐assembled Cu nanostructures on ZnO thin films is reported. The incident lights are effectively confined in ZnO photoactive layers with the existence of the uplayer Cu nanostructures, and the interdiffusion of Cu atoms during fabrication of the Cu nanostructures can improve the carrier transfer in ZnO thin films. The optical properties of the hybrid architectures are successfully tailored over a control of the geometric evolution of the Cu nanostructures, resulting in significantly enhanced photocurrent and responsivity of 2.26 mA and 234 A W−1 under a UV light illumination of 0.62 mW cm−2 at 10 V, respectively. The photodetectors also exhibit excellent reproducibility, stability, and UV–visible rejection ratio (R370 nm/R500 nm) of ≈370, offering an approach of high‐performance UV photodetectors for practical applications.

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Recent Progress in Solar‐Blind Deep‐Ultraviolet Photodetectors Based on Inorganic Ultrawide Bandgap Semiconductors

Xie

Tong

et al. 2019

Adv Funct Materials

408

261

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Due to its significant applications in many relevant fields, light detection in the solar-blind deep-ultraviolet (DUV) wavelength region is a subject of great interest for both scientific and industrial communities. The rapid advances in preparing high-quality ultrawide-bandgap (UWBG) semiconductors have enabled the realization of various high-performance DUV photodetectors (DUVPDs) with different geometries, which provide an avenue for circumventing numerous disadvantages in traditional DUV detectors. This article presents a comprehensive review of the applications of inorganic UWBG semiconductors for solar-blind DUV light detection in the past several decades. Different kinds of DUVPDs, which are based on varied UWBG semiconductors including Ga 2 O 3 , Mg x Zn 1−x O, III-nitride compounds (Al x Ga 1−x N/AlN and BN), diamond, etc., and operate on different working principles, are introduced and discussed systematically. Some emerging techniques to optimize device performance are addressed as well. Finally, the existing techniques are summarized and future challenges are proposed in order to shed light on development in this critical research field.with energy much higher than the semiconductor bandgap. Moreover, due to light absorption by the surface passivation layers, typically Si oxide, quantum efficiency in the DUV range is greatly reduced. The passivation layers are also easily degraded by UV illumination. Finally, for highly sensitive UV photodetection, the detectors need to be cooled to reduce dark current; the cooled detectors, however, behave like cold traps for contaminants which degrade the detectivity.In the past two decades, the emergence of UV photodetectors based on wide-bandgap (WBG) semiconductors has opened up an avenue to circumvent the above-mentioned dilemma. The WBG semiconductors such as SiC, GaN, and some group II-V compounds, typically have bandgaps exceeding ≈3.10 eV, enabling room-temperature detectors to possess fast response speed, and offering intrinsic visible-blindness (response cutoff wavelength: ≈400 nm). [14][15][16] Moreover, these semiconductors generally possess significantly higher thermal conductivity than Si, which renders them suitable for operation in harsh environments (e.g., high temperature and high power). The electron velocity of these materials at large electric fields is generally higher than that of common semiconductors, although WBG semiconductors exhibit relatively lower electron and hole mobilities. Compared with the abovementioned conventional WBG semiconductors, ultrawide-bandgap (UWBG) semiconductors, as the next generation of semiconductor materials with bandgaps significantly wider than the 3.4 eV of GaN, are particularly suitable for solar-blind DUV light detection. [17][18][19][20]

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High-performance solar-blind flexible deep-UV photodetectors based on quantum dots synthesized by femtosecond-laser ablation

Abstract: Ajia I, et al. (2018) Highperformance solar-blind flexible deep-UV photodetectors based on quantum dots synthesized by femtosecond-laser ablation.

Cited by 79 publications

References 48 publications

Density Functional Theory Studies of Zn12O12 Clusters Doped with Mg/Eu and Defect Complexes

Density Functional Theory Studies of Zn12O12 Clusters Doped with Mg/Eu and Defect Complexes

Ultrahigh Responsivity UV Photodetector Based on Cu Nanostructure/ZnO QD Hybrid Architectures

Recent Progress in Solar‐Blind Deep‐Ultraviolet Photodetectors Based on Inorganic Ultrawide Bandgap Semiconductors

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