Pulse laser deposition of epitaxial TiO 2 thin films for high-performance ultraviolet photodetectors

Zhang, Zifeng; Wong, Lai Mun; Zhang, Zhiwei; Zhang, Wu; Wang, Xinbo; Chi, Dongzhi; Hong, Rongdun; Yang, Weifeng

doi:10.1016/j.apsusc.2015.07.031

Cited by 24 publications

(6 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These advantages come from the ability to control the parameters as laser power, pulse frequency, substrate temperature, rate deposition, pressure deposition, the distance between target and substrate, etc. [7,9]. In order to obtain various morphology and properties of the materials through the PLD technique, the deposition pressure is an important parameter influencing this feature [3,10,11].…”

Section: Introductionmentioning

confidence: 99%

Development of Pd/TiO2 Porous Layers by Pulsed Laser Deposition for Surface Acoustic Wave H2 Gas Sensor

Constantinoiu

Viespe

2020

Nanomaterials

View full text Add to dashboard Cite

The influence of sensitive porous films obtained by pulsed laser deposition (PLD) on the response of surface acoustic wave (SAW) sensors on hydrogen at room temperature (RT) was studied. Monolayer films of TiO 2 and bilayer films of Pd/TiO 2 were deposited on the quartz substrates of SAW sensors. By varying the oxygen and argon pressure in the PLD deposition chamber, different morphologies of the sensitive films were obtained, which were analyzed based on scanning electron microscopy (SEM) images. SAW sensors were realized with different porosity degrees, and these were tested at different hydrogen concentrations. It has been confirmed that the high porosity of the film and the bilayer structure leads to a higher frequency shift and allow the possibility to make tests at lower concentrations. Thus, the best sensor, Pd-1500/TiO 2 -600, with the deposition pressure of 600 mTorr for TiO 2 and 1500 mTorr for Pd, had a frequency shift of 1.8 kHz at 2% hydrogen concentration, a sensitivity of 0.10 Hz/ppm and a limit of detection (LOD) of 1210 ppm. SAW sensors based on such porous films allow the detection of hydrogen but also of other gases at RT, and by PLD method such sensitive porous and nanostructured films can be easily developed.

show abstract

Section: Introductionmentioning

confidence: 99%

Development of Pd/TiO2 Porous Layers by Pulsed Laser Deposition for Surface Acoustic Wave H2 Gas Sensor

Constantinoiu

Viespe

2020

Nanomaterials

View full text Add to dashboard Cite

show abstract

“…[14][15][16][17] As shown in Table III, we observed that the maximum responsivity in our device had a significant improvement compared to the listed devices. …”

Section: The Responsivity (R) Of a Detector Is Defined In Equationmentioning

confidence: 41%

Characterization of High Mg Content MgZnO Ultraviolet Photodetectors with Noise Properties

Chang

Hsu

et al. 2016

ECS J. Solid State Sci. Technol.

View full text Add to dashboard Cite

This study examined MgZnO thin films grown on quartz substrates using radio frequency magnetron sputtering. These films with varying Mg content were used to fabricate metal-semiconductor-metal (MSM) ultraviolet (UV) photodetectors (PDs). The best sample with optimized properties was obtained using a Mg content of 20%. The relatively high Mg content could effectively suppress the dark current to a value of the order of 10 −13 A. The PD exhibited an on-off ratio of seven orders of magnitude; its photo-responsivity increased with the increasing Mg content, which caused the suppression of the dark current. The UV-to-visible rejection ratio could be up to five orders of magnitude. Furthermore, the noise equivalent power (NEP) and the normalized detectivity (D * ) of the PD fabricated with 20% Mg were determined as 6.6 × 10 −15 W and 6.5 × 10 −14 cmHz 0.5 W −1 , respectively. These results indicate that an increase in the Mg content could reduce the dark current and the noise by effectively suppressing the donor-like defects.In recent years, ultraviolet (UV) photodetectors (PDs) have attracted considerable interest owing to their newly developed commercial applications in areas such as flame sensing, missile detection, and communications. 1 As an oxide semiconductor material exhibiting a continuous tunable wide bandgap from 3.37 eV to 7.8 eV, wurtzite MgZnO has demonstrated its versatile functionality in various device applications. 2,3 Thus, research into novel ZnO-related materials has increased. MgZnO is similar to aluminum gallium nitride (AlGaN); it is an ideal material for UV photodetectors due to its wide band-gap, high radiation hardness, and low growth temperatures. In addition, this material is abundant in nature, inexpensive, and eco-friendly. Moreover, Mg has a stronger affinity toward oxygen than to Zn in ZnO, which leads to a decrease in the number of zinc interstitials and oxygen vacancies owing to the higher ionic character of the Mg-O bonds than that of the Zn-O bonds (the fractional ionic character is 0.61 for ZnO and 0.84 for MgO). 4,5 The ionic radii of Mg 2+ and Zn 2+ are similar (Mg 2+ : 0.57 Å and Zn 2+ : 0.60 Å). It has been reported that the addition of Mg 2+ to Zn 2+ site did not cause significant lattice disorder, and films of Mg x Zn 1−x O could be deposited up to x = 0.33 without segregation of the MgO phase. 6 Such wide and tunable bandgap is expected to enable MgZnO-based UV photodetector to be applicable. Till now, MgZnO-based UV photodetectors have been fabricated using different methods, such as metal organic chemical vapor deposition (MOCVD), RF-sputtering, and molecular beam epitaxy (MBE). 7 MgZnO-based UV photodetectors have been fabricated with various types, such as PN junction, PIN Schottky barrier and MSM UV photodetector. 8-10 Furthermore, MSM photodetectors have several attractive features that make them ideal candidates for space applications, such as a low dark current, high responsivity, large bandwidth, and low noise densities. Solar or visible-blind MgZnO PDs have been fa...

show abstract

“…In 2015, Z. Zhang et al reported a high quality TiO 2 epitaxial layer grown on a LaAlO 3 substrate by pulsed laser deposition. A prototype of a TiO 2 -based metal-semiconductor-metal ultraviolet (UV) photodetector was prepared using Au as the Schottky contact metal [269]. Compared with bulk materials, CeO 2 films with nanostructures have potential applications in nanoscale devices.…”

Section: Laser Equimentmentioning

confidence: 99%

The Fabrication of Micro/Nano Structures by Laser Machining

Yang

Wei

et al. 2019

Nanomaterials

View full text Add to dashboard Cite

Micro/nano structures have unique optical, electrical, magnetic, and thermal properties. Studies on the preparation of micro/nano structures are of considerable research value and broad development prospects. Several micro/nano structure preparation techniques have already been developed, such as photolithography, electron beam lithography, focused ion beam techniques, nanoimprint techniques. However, the available geometries directly implemented by those means are limited to the 2D mode. Laser machining, a new technology for micro/nano structural preparation, has received great attention in recent years for its wide application to almost all types of materials through a scalable, one-step method, and its unique 3D processing capabilities, high manufacturing resolution and high designability. In addition, micro/nano structures prepared by laser machining have a wide range of applications in photonics, Surface plasma resonance, optoelectronics, biochemical sensing, micro/nanofluidics, photofluidics, biomedical, and associated fields. In this paper, updated achievements of laser-assisted fabrication of micro/nano structures are reviewed and summarized. It focuses on the researchers’ findings, and analyzes materials, morphology, possible applications and laser machining of micro/nano structures in detail. Seven kinds of materials are generalized, including metal, organics or polymers, semiconductors, glass, oxides, carbon materials, and piezoelectric materials. In the end, further prospects to the future of laser machining are proposed.

show abstract

Pulse laser deposition of epitaxial TiO 2 thin films for high-performance ultraviolet photodetectors

Cited by 24 publications

References 42 publications

Development of Pd/TiO2 Porous Layers by Pulsed Laser Deposition for Surface Acoustic Wave H2 Gas Sensor

Development of Pd/TiO2 Porous Layers by Pulsed Laser Deposition for Surface Acoustic Wave H2 Gas Sensor

Characterization of High Mg Content MgZnO Ultraviolet Photodetectors with Noise Properties

The Fabrication of Micro/Nano Structures by Laser Machining

Contact Info

Product

Resources

About