scholarly journals Review of Si-Based GeSn CVD Growth and Optoelectronic Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2556
Author(s):  
Yuanhao Miao ◽  
Guilei Wang ◽  
Zhenzhen Kong ◽  
Buqing Xu ◽  
Xuewei Zhao ◽  
...  
Keyword(s):  
High Performance ◽  
Ohmic Contacts ◽  
Molecular Beam ◽  
Vapour Deposition ◽  
High Efficiency ◽  
Chemical Vapor ◽  
Growth Method ◽  
Cvd Growth ◽  
Optoelectronic Applications

GeSn alloys have already attracted extensive attention due to their excellent properties and wide-ranging electronic and optoelectronic applications. Both theoretical and experimental results have shown that direct bandgap GeSn alloys are preferable for Si-based, high-efficiency light source applications. For the abovementioned purposes, molecular beam epitaxy (MBE), physical vapour deposition (PVD), and chemical vapor deposition (CVD) technologies have been extensively explored to grow high-quality GeSn alloys. However, CVD is the dominant growth method in the industry, and it is therefore more easily transferred. This review is focused on the recent progress in GeSn CVD growth (including ion implantation, in situ doping technology, and ohmic contacts), GeSn detectors, GeSn lasers, and GeSn transistors. These review results will provide huge advancements for the research and development of high-performance electronic and optoelectronic devices.

scholarly journals Bio-Separated and Gate-Free 2D MoS2 Biosensor Array for Ultrasensitive Detection of BRCA1

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 545
Author(s):  
Yi Zhang ◽  
Wei Jiang ◽  
Dezhi Feng ◽  
Chenguang Wang ◽  
Yi Xu ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Chemical Vapor ◽  
Signal Interference ◽  
Ultrasensitive Detection ◽  
Chemical Vapor Deposition Growth ◽  
Biosensor Array ◽  
Growth Method ◽  
Biological Modification ◽  
Biological Solutions

2D molybdenum disulfide (MoS2)-based thin film transistors are widely used in biosensing, and many efforts have been made to improve the detection limit and linear range. However, in addition to the complexity of device technology and biological modification, the compatibility of the physical device with biological solutions and device reusability have rarely been considered. Herein, we designed and synthesized an array of MoS2 by employing a simple-patterned chemical vapor deposition growth method and meanwhile exploited a one-step biomodification in a sensing pad based on DNA tetrahedron probes to form a bio-separated sensing part. This solves the signal interference, solution erosion, and instability of semiconductor-based biosensors after contacting biological solutions, and also allows physical devices to be reused. Furthermore, the gate-free detection structure that we first proposed for DNA (BRCA1) detection demonstrates ultrasensitive detection over a broad range of 1 fM to 1 μM with a good linear response of R2 = 0.98. Our findings provide a practical solution for high-performance, low-cost, biocompatible, reusable, and bio-separated biosensor platforms.

In Situ Observation of Nucleation and Growth of Carbon Nanotubes from Iron Carbide Nanoparticles

2008 ◽  
Vol 1142 ◽  
Author(s):  
Hideto Yoshida ◽  
Seiji Takeda ◽  
Tetsuya Uchiyama ◽  
Hideo Kohno ◽  
Yoshikazu Homma
Keyword(s):  
Carbon Nanotubes ◽  
Iron Carbide ◽  
Bulk Diffusion ◽  
Chemical Vapor ◽  
Nucleation And Growth ◽  
Atomic Scale ◽  
In Situ Observation ◽  
Transmission Electron ◽  
Cvd Growth

ABSTRACTNucleation and growth processes of carbon nanotubes (CNTs) in iron catalyzed chemical vapor deposition (CVD) have been observed by means of in-situ environmental transmission electron microscopy. Our atomic scale observations demonstrate that solid state iron carbide (Fe3C) nanoparticles act as catalyst for the CVD growth of CNTs. Iron carbide nanoparticles are structurally fluctuated in CVD condition. Growth of CNTs can be simply explained by bulk diffusion of carbon atoms since nanoparticles are carbide.

Migration-Enhanced Molecular Beam Epitaxial Growth and Characterization of GaAs on Si Substrates

1988 ◽  
Vol 144 ◽  
Author(s):  
J.H. Kim ◽  
S. Sakai ◽  
J.K. Liu ◽  
G. Raohakrishnan ◽  
S.S. Chang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Cross Sectional ◽  
Light Emitting ◽  
Si Substrates ◽  
Molecular Beam Epitaxial

ABSTRACTWe first report on migration-enhanced molecular beam epitaxial (MEMBE) growth and characterization of the GaAs layers on Si substrates (GaAs/Si). Excellent surface morphology GaAs layers were successfully grown on (100) Sisubstrates misoriented 4 toward [110] direction. The MEMBE growth method isdescribed and material properties are compared with those of normal two-step MBE-grown or in-situ annealed layers. Micrographs of cross-sectional view transmission electron microscopy (TEM) and scanning surface electron microscopy (SEM) of MEMBE-grown GaAs/Si showed dislocation densities of 107 cm-2 over ten times lower than those of two-step MBE-grown or in-situ annealedlayers. AlGaAs/GaAs double heterostructure lasers and light-emitting diodeshave been successfully grown on MEMBE GaAs/Si by both metal organic chemical vapor deposition and liquid phase epitaxy. MOCVD-grown lasers showed peak output power as high as 184 mW/facet, pulsed threshold currents as low as150 mA at 300 K, and differential quantum efficiencies of up to 30 %. The LPE-grown light-emitting diodes showed output powers of 1.5 mW and external quantum efficiencies of 3.3 mW/A per facet.

scholarly journals In-situ formed and low-temperature deposited Nb: TiO2 compact-mesoporous layer for hysteresis-less perovskite solar cells with high performance

2020 ◽  
Author(s):  
Miao Yu ◽  
Haoxuan Sun ◽  
Xiaona Huang ◽  
Yichao Yan ◽  
Wanli Zhang
Keyword(s):  
Solar Cells ◽  
Low Temperature ◽  
High Performance ◽  
High Efficiency ◽  
Perovskite Solar Cells ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
High Power Conversion Efficiency ◽  
Mesoporous Structures

Abstract Recently, reported perovskite solar cells (PSCs) with high power conversion efficiency (PCE) are mostly based on mesoporous structures containing mesoporous titanium oxide (TiO 2 ) which is the main factor to reduce the overall hysteresis. However, existing fabrication approaches for mesoporous TiO 2 generally require a high temperature (>450 °C) annealing process. Moreover, there is still plenty of scope for improvement in terms of increasing the electron conductivity and reducing the carrier recombination. Herein, a facile one-step, in situ and low-temperature method was developed to prepare an Nb:TiO 2 compact-mesoporous layer to serve as both a scaffold and an electron transport layer (ETL) in PSCs. The Nb:TiO 2 compact-mesoporous layer based PSCs exhibit suppressed hysteresis, which is attributed to the synergistic effect of the large interface surface area caused by nano-pin morphology on the surface and the improved carrier transportation caused by the presence of Nb. Such a high-quality compact-mesoporous layer allows the PSC achieve a remarkable PCE of 19.74%. This work promises an effective approach for creating hysteresis-less and high-efficiency PSCs based on compact-mesoporous structures with lower energy consumption and cost.

Phase selective CVD growth and photoinduced 1T → 1H phase transition in a WS2 monolayer

2020 ◽  
Vol 8 (30) ◽  
pp. 10438-10447
Author(s):  
Deepa Thakur ◽  
Pawan Kumar ◽  
Viswanath Balakrishnan
Keyword(s):  
Phase Transition ◽  
Fluorescence Microscopy ◽  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Cvd Growth ◽  
Ws2 Monolayer

We report the direct chemical vapour deposition (CVD) growth of the metastable 1T phase of a WS2 monolayer and the in situ phase transition characteristics with the aid of Raman, photoluminescence and fluorescence microscopy.

scholarly journals High-performance monolayer MoS2 photodetector enabled by oxide stress liner using scalable chemical vapor growth method

Nanophotonics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1981-1991 ◽  
Author(s):  
Zhiwen Li ◽  
Jing Wu ◽  
Cong Wang ◽  
Han Zhang ◽  
Wenjie Yu ◽  
...  
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Surface Defects ◽  
Volume Ratio ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
Light Illumination ◽  
Vapor Growth ◽  
Layer Deposition ◽  
Growth Method

AbstractMoS2, as a typical representative of two-dimensional semiconductors, has been explored extensively in applications of optoelectronic devices because of its adjustable bandgap. However, to date, the performance of the fabricated photodetectors has been very sensitive to the surrounding environment owing to the large surface-to-volume ratio. In this work, we report on large-scale, high-performance monolayer MoS2 photodetectors covered with a 3-nm Al2O3 layer grown by atomic layer deposition. In comparison with the device without the Al2O3 stress liner, both the photocurrent and responsivity are improved by over 10 times under 460-nm light illumination, which is due to the tensile strain induced by the Al2O3 layer. Further characterization demonstrated state-of-the-art performance of the device with a responsivity of 16.103 A W−1, gain of 191.80, NEP of 7.96 × 10−15 W Hz−1/2, and detectivity of 2.73 × 1010 Jones. Meanwhile, the response rise time of the photodetector also reduced greatly because of the increased electron mobility and reduced surface defects due to the Al2O3 stress liner. Our results demonstrate the potential application of large-scale strained monolayer MoS2 photodetectors in next-generation imaging systems.

Cobalt and nitrogen co-doped Ni3S2 nanoflowers on nickel foam as high-efficiency electrocatalysts for overall water splitting in alkaline media

2021 ◽  
Author(s):  
Xiaoqiang Du ◽  
Guangyu Ma ◽  
Xiaoshuang Zhang
Keyword(s):  
Water Splitting ◽  
High Performance ◽  
High Efficiency ◽  
Nickel Foam ◽  
Water Electrolysis ◽  
Cost Effective ◽  
Alkaline Media ◽  
Co Doping ◽  
Production Industry

The development of high-performance and cost-effective bifunctional water splitting catalysts are of enormous significance to the hydrogen production industry from water electrolysis. Herein, an in-situ Co and N co-doping method...

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