scholarly journals Self-rolling and light-trapping in flexible quantum well–embedded nanomembranes for wide-angle infrared photodetectors

2016 ◽  
Vol 2 (8) ◽  
pp. e1600027 ◽  
Author(s):  
Han Wang ◽  
Honglou Zhen ◽  
Shilong Li ◽  
Youliang Jing ◽  
Gaoshan Huang ◽  
...  

Three-dimensional (3D) design and manufacturing enable flexible nanomembranes to deliver unique properties and applications in flexible electronics, photovoltaics, and photonics. We demonstrate that a quantum well (QW)–embedded nanomembrane in a rolled-up geometry facilitates a 3D QW infrared photodetector (QWIP) device with enhanced responsivity and detectivity. Circular geometry of nanomembrane rolls provides the light coupling route; thus, there are no external light coupling structures, which are normally necessary for QWIPs. This 3D QWIP device under tube-based light-trapping mode presents broadband enhancement of coupling efficiency and omnidirectional detection under a wide incident angle (±70°), offering a unique solution to high-performance focal plane array. The winding number of these rolled-up QWIPs provides well-tunable blackbody photocurrents and responsivity. 3D self-assembly of functional nanomembranes offers a new path for high conversion efficiency between light and electricity in photodetectors, solar cells, and light-emitting diodes.

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2581
Author(s):  
Dan Su ◽  
Lei Lv ◽  
Yi Yang ◽  
Huan-Li Zhou ◽  
Sami Iqbal ◽  
...  

Nanomaterials and nanostructures provide new opportunities to achieve high-performance optical and optoelectronic devices. Three-dimensional (3D) surfaces commonly exist in those devices (such as light-trapping structures or intrinsic grains), and here, we propose requests for nanoscale control over nanostructures on 3D substrates. In this paper, a simple self-assembly strategy of nanospheres for 3D substrates is demonstrated, featuring controllable density (from sparse to close-packed) and controllable layer (from a monolayer to multi-layers). Taking the assembly of wavelength-scale SiO2 nanospheres as an example, it has been found that textured 3D substrate promotes close-packed SiO2 spheres compared to the planar substrate. Distribution density and layers of SiO2 coating can be well controlled by tuning the assembly time and repeating the assembly process. With such a versatile strategy, the enhancement effects of SiO2 coating on textured silicon solar cells were systematically examined by varying assembly conditions. It was found that the close-packed SiO2 monolayer yielded a maximum relative efficiency enhancement of 9.35%. Combining simulation and macro/micro optical measurements, we attributed the enhancement to the nanosphere-induced concentration and anti-reflection of incident light. The proposed self-assembly strategy provides a facile and cost-effective approach for engineering nanomaterials at 3D interfaces.


Micromachines ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 13 ◽  
Author(s):  
Bin Zhang ◽  
Jaehyun Lee ◽  
Mincheol Kim ◽  
Naeeung Lee ◽  
Hyungdong Lee ◽  
...  

The macroscopic assembly of two-dimensional materials into a laminar structure has received considerable attention because it improves both the mechanical and chemical properties of the original materials. However, conventional manufacturing methods have certain limitations in that they require a high temperature process, use toxic solvents, and are considerably time consuming. Here, we present a new system for the self-assembly of layer-by-layer (LBL) graphene oxide (GO) via an electrohydrodynamic (EHD) jet printing technique. During printing, the orientation of GO flakes can be controlled by the velocity distribution of liquid jet and electric field-induced alignment spontaneously. Closely-packed GO patterns with an ordered laminar structure can be rapidly realized using an interfacial assembly process on the substrates. The surface roughness and electrical conductivity of the LBL structure were significantly improved compared with conventional dispensing methods. We further applied this technique to fabricate a reduced graphene oxide (r-GO)-based supercapacitor and a three-dimensional (3D) metallic grid hybrid ammonia sensor. We present the EHD-assisted assembly of laminar r-GO structures as a new platform for preparing high-performance energy storage devices and sensors.


2015 ◽  
Vol 3 (4) ◽  
pp. 1540-1548 ◽  
Author(s):  
Sheng Zhu ◽  
Hui Zhang ◽  
Ping Chen ◽  
Lin-Hui Nie ◽  
Chuan-Hao Li ◽  
...  

A facile protocol for the self-assembly of the rGO/β-MnO2 hybrid hydrogel with ultrafine structure and precise control of mass-loading for high performance supercapacitors is reported.


2020 ◽  
Author(s):  
Haozhen Dou ◽  
Mi Xu ◽  
Baoyu Wang ◽  
Zhen Zhang ◽  
Guobin Wen ◽  
...  

Abstract Cellular membranes provide ideal archetypes for molecule or ion separations with sub-angstrom scale precision, which are featured with both extremely high permeability and selectivity due to the well-defined membrane protein channels. However, the development of bioinspired membranes with artificial channels for sub-angstrom scale ethylene/ethane (0.416 nm / 0.443 nm) separation remains an uncharted territory and a significant challenge. Herein, a bioinspired nano-ordered liquid membrane is constructed by a facile ion/molecule self-assembly strategy for highly efficient ethylene/ethane separation, which mimics the structure of cellular membrane elegantly and possesses plenty of three-dimensional (3D) nanochannels. The elaborate regulation of non-covalent interactions by optimizing the ion/molecule compositions within membrane confers the nano-ordered liquid structure with interpenetrating and bi-continuous apolar domains and polar domains, which results in the formation of regular carrier wires and enormous 3D interconnected ethylene transport nanochannels. By virtue of these 3D nanochannels, the bioinspired nano-ordered liquid membrane manifests simultaneously super-high selectivity, excellent permeance and long-term stability, which exceeds previously reported ethylene/ethane separation membranes. This methodology in this work for construction of bioinspired membrane with tunable 3D nanochannels through ion/molecule self-assembly will enlighten the design and development of high-performance separation membranes for angstrom/sub-angstrom scale ion or molecule separations.


2021 ◽  
Vol 118 (33) ◽  
pp. e2101296118
Author(s):  
Isabelle Su ◽  
Neosha Narayanan ◽  
Marcos A. Logrono ◽  
Kai Guo ◽  
Ally Bisshop ◽  
...  

Spiders are nature’s engineers that build lightweight and high-performance web architectures often several times their size and with very few supports; however, little is known about web mechanics and geometries throughout construction, especially for three-dimensional (3D) spider webs. In this work, we investigate the structure and mechanics for a Tidarren sisyphoides spider web at varying stages of construction. This is accomplished by imaging, modeling, and simulations throughout the web-building process to capture changes in the natural web geometry and the mechanical properties. We show that the foundation of the web geometry, strength, and functionality is created during the first 2 d of construction, after which the spider reinforces the existing network with limited expansion of the structure within the frame. A better understanding of the biological and mechanical performance of the 3D spider web under construction could inspire sustainable robust and resilient fiber networks, complex materials, structures, scaffolding, and self-assembly strategies for hierarchical structures and inspire additive manufacturing methods such as 3D printing as well as inspire artistic and architectural and engineering applications.


Author(s):  
Caleb Serafy ◽  
Ankur Srivastava ◽  
Avram Bar-Cohen ◽  
Donald Yeung

Three-dimensional integration (3D IC) is a new technology that shows great potential for high performance and energy efficiency. However past work has shown that 3D ICs suffer from serious thermal issues, and advanced cooling solutions such as micro-fluidic cooling are necessary to realize the true potential of these systems. The interactions between thermal, electrical and physical aspects of a 3D design with micro-fluidic cooling are substantial, and a comprehensive co-design approach to address them simultaneously is a must. Such co-design techniques are required throughout the design process, including during architectural design space exploration (DSE) in order to ensure that optimal design choices are not overlooked. In this paper we propose a DSE framework for 3D CPUs with micro-fluidic cooling that applies electro-thermal optimization techniques to the circuit layout and the heatsink design. By considering such physical optimization techniques we provide a more accurate view of a 3D architecture’s thermal and timing feasibility, as well as its performance and energy efficiency. Using our proposed thermo-electrical-physical co-design DSE framework we are able to improve performance by 1.54x and energy efficiency by 1.26x.


2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Nathan B. Crane ◽  
Patrick McKnight

Thermoelectric devices have many scaling benefits that motivate miniaturization, but assembly of small components is a significant challenge. Self-assembly provides a promising method for integrating very small elements. However, it introduces the possibility of stochastic errors with significant performance impacts. This work presents a method to estimate the impact of these errors on system performance. Equivalent thermoelectric properties are developed that adjust for the effect of missing elements in one-dimensional thermoelectric models. The models show that the thermoelectric devices can accommodate significant self-assembly errors by incorporation of redundant electrical paths. The model shows nearly linear decline in effective power factor with declining assembly accuracy, but the effective figure of merit (ZT) is relatively insensitive to assembly errors. Predictions from the modified one-dimensional model agree well with three-dimensional finite element simulations. This work identifies two basic strategies for how devices such as thermoelectric could be designed for self-assembly and demonstrates that it is possible to achieve high performance despite self-assembly process errors.


2014 ◽  
Vol 2 (34) ◽  
pp. 13801-13804 ◽  
Author(s):  
Wenjun Hao ◽  
Shimou Chen ◽  
Yingjun Cai ◽  
Lan Zhang ◽  
Zengxi Li ◽  
...  

3D hierarchical pompon-like Co3O4 porous spheres were produced by a simple hydrothermal method. The 3D structure is composed of many nanowires which gathered as a ring in the centre and fanned out via a special self-assembly fashion, resulting in good lithium ion battery performance.


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