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Semitransparent thin-film solar cells, especially those fabricated directly on building materials, have attracted much interest in the continuously increasing demands of building-integrated photovoltaic (BIPV) applications. Herein, radial junction (RJ)-structured hydrogenated amorphous silicon (a-Si:H) thin-film solar cells, directly constructed upon silicon nanowires (SiNWs) grown by a vapor–liquid–solid (VLS) process on the rough surface of the tinplate substrates, have been successfully demonstrated. After optimizing the SiNW density, an efficiency of 5.89% can be achieved, with an average value of 5.38 ± 0.39%. Compared to the conventional thin-film photovoltaics on glass substrates, the semitransparent RJ-structured thin-film solar cells on the laser-cutting tinplate substrates have a lower reflectivity, an adjustable/designable light transmission, as well as excellent mechanical stability. More importantly, tinplate and other steel/metal substrates can be used as construction materials; thus, the overall costs, including fabrication and installation costs as well as the building construction cost, can be largely reduced. These results highlight the promising potential of the RJ thin film technology on laser-cutting steel/metal substrates to fabricate low-cost, low-reflection, and mechanically stable semitransparent thin-film BIPV devices. [ABSTRACT FROM AUTHOR]

A Schottky barrier tunneling field-effect transistor (SBT FET) built upon catalytically grown ultrathin silicon nanowires (SiNWs) offers a preferable low-temperature routine to construct top device layers for monolithic three-dimensional (3D) integration technology, but there still remain several peculiar electronic transport behaviors that need to be better understood. In this work, a high-performance SBT FET was fabricated based on orderly SiNWs grown via the in-plane solid–liquid–solid (IPSLSL) mechanism, achieving an Ion/Ioff ratio of 106 and a SS of 150 mV/dec. The as-fabricated device, with SBT contacts between SiNWs and Pt/Au source-drain electrodes, was analyzed and compared to a three-dimensional numerical model built via the TCAD simulator to extract the actual energy band profile and the bias distribution in the SBT FET, as well as the hole carrier mobility in the catalytic SiNW channels. This comparative investigation also reveals the limiting factors for the SBT transport and explains well the observed peculiar channel-bias-dependent drain-induced barrier-lowering (DIBL) behavior. These results provide an in-depth understanding of SBT FET and lay a solid basis for its future applications in high-performance logic and in-memory computing in advanced 3D architecture. [ABSTRACT FROM AUTHOR]

A robust radial junction (RJ) structure directly constructed upon the surface of a flexible Al foil substrate shows a promising potential to boost wearable and portable applications, where the silicon nanowire (SiNW) supported multilayer has proven beneficial in excellent mechanical stability and sufficient light harvesting. Assigned to the beneficial backreflection contributed by the Al foil, a much larger light current can be achieved than that on glass. While a comprehensive understanding of the light absorption under the backreflection of the substrate remains mainly unexplored. Herein, a straightforward comparison of light absorption of RJ units on Al and glass substrates, within a theoretical framework based on a finite-element simulation, is performed. Then, taking SiNW geometric parameters and i-layer thickness into account, the evolutions of light harvesting and the external quantum efficiency curves are systematically studied. These results indicate that, under the backreflection of the substrate, the light absorption shows a reduced dependency on SiNW geometry and i-layer thickness to some extent, laying a critical basis to establish a simpler/easier fabrication process for high-performance flexible RJ thin film photovoltaics. [ABSTRACT FROM AUTHOR]

Recent years have witnessed increasing efforts devoted to the growth, assembly and integration of quasi-one dimensional (1D) nanowires (NWs), as fundamental building blocks in advanced three-dimensional (3D) architecture, to explore a series of novel nanoelectronic and sensor applications. An important motivation behind is to boost the integration density of the electronic devices by stacking more functional units in the out-of-plane z- direction, where the NWs are supposed to be patterned or grown as vertically standing or laterally stacked channels to minimize their footprint area. The other driving force is derived from the unique possibility of engineering the 1D NWs into more complex, as well as more functional, 3D nanostructures, such as helical springs and kinked probes, which are ideal nanostructures for developping advanced nanoelectromechanical system (NEMS), bio-sensing and manipulation applications. This Review will first examine the recent progresses made in the construction of 3D nano electronic devices, as well as the new fabrication and growth technologies established to enable an efficient 3D integration of the vertically standing or laterally stacked NW channels. Then, the different approaches to produce and tailor more sophisticated 3D helical springs or purposely-designed nanoprobes will be revisited, together with their applications in NEMS resonators, bio sensors and stimulators in neural system. [ABSTRACT FROM AUTHOR]

Quasi‐1D silicon nanowires (SiNWs) field effect transistors (FETs) integrated upon large‐area elastomers are advantageous candidates for developing various high‐performance stretchable electronics and displays. In this work, it is demonstrated that an orderly array of slim SiNW channels, with a diameter of <80 nm, can be precisely grown into desired locations via an in‐plane solid‐liquid‐solid (IPSLS) mechanism, and reliably batch‐transferred onto large area polydimethylsiloxane (PDMS) elastomers. Within an optimized discrete FETs‐on‐islands architecture, the SiNW‐FETs can sustain large stretching strains up to 50% and repetitive testing for more than 1000 cycles (under 20% strain), while achieving a high hole carrier mobility, Ion/Ioff current ratio and subthreshold swing (SS) of ≈70 cm2 V−1 s−1, >105 and 134 ‐ 277 mV decade−1, respectively, working stably in an ambient environment over 270 days without any passivation protection. These results indicate a promising new routine to batch‐manufacture and integrate high‐performance, scalable and stretchable SiNW‐FET electronics that can work stably in harsh and large‐strain environments, which is a key capability for future practical flexible display and wearable electronic applications. [ABSTRACT FROM AUTHOR]

Ultrathin silicon nanowires (SiNWs) are ideal 1D channels to construct high performance nanoelectronics and sensors. We here report on a high-density catalytic growth of orderly ultrathin SiNWs, with diameter down to and narrow NW-to-NW spacing of only ∼80 nm, without the use of high-resolution lithography. This has been accomplished via a terrace-confined strategy, where tiny indium (In) droplets move on sidewall terraces to absorb precoated amorphous Si layer as precursor and produce self-aligned SiNW array. It is found that, under proper parameter control, a tighter terrace-step confinement can help to scale the dimensions of the SiNW array down to the extremes that have not been reported before, while maintaining still a stable guiding growth over complex contours. Prototype SiNW field effect transistors demonstrate a high Ion/Ioff current ratio ∼107, low leakage current of ∼0.3 pA and steep subthreshold swing of 220 mV dec−1. These results highlight the unexplored potential of catalytic growth in advanced nanostructure fabrication that is highly relevant for scalable SiNW logic and sensor applications. [ABSTRACT FROM AUTHOR]

A biotemplate of grapefruit exocarp was used to synthesis porous hierarchical SnO 2 and its gas sensing properties were investigated in this manuscript. Biomorphic SnO 2 with lamellar and plicated membranes and porous walls were synthesized by using grapefruit exocarp template combining with ultrasonic shaking and following calcination. The porous hierarchical structure of biomorphic SnO 2 was characterized by field emission scanning electron microscope, transmission electron microscopy, nitrogen adsorption–desorption isotherm, etc. The biomorphic SnO 2 exhibits small grain size around 10 nm, a relatively large BET surface area and mesoporosity. Growth mechanism of biomorphic SnO 2 was proposed. The sensing properties of the biomorphic SnO 2 to formaldehyde vapor were measured. The optimal operating temperature of the sensor was 200 °C and the response value of the sensor to 10 ppm formaldehyde was 50. The sensor showed a good selectivity to formaldehyde in methanol, acetone, toluene, benzene and ammonia. The stability and the effect of humidity of the sensor were also tested. The gas sensing mechanism of the biomorphic SnO 2 to formaldehyde was analyzed briefly. [ABSTRACT FROM AUTHOR]

High performance and robustness are the key factors to boosting wearable and portable applications. Although the 1D crystal structure makes the Sb 2 Se 3 thin film more tolerant to physical deformation upon bending, the conventional planar structures still cannot undergo repeated mechanical bending due to the induced stress/strain inside devices, which can be well addressed by constructing three-dimensional nanostructures. Besides, the electron diffusion length has two values, 0.3 μm in the [221] direction and 1.7 μm in the [001] direction, in the Sb 2 Se 3 thin film, which limits the absorber thickness, for getting an effective carrier collection; thus, a strong light trapping effect enabling sufficient light harvesting is needed to allow the use of a very thin light absorption layer. Herein, the nanoconed Sb 2 Se 3 solar cells have been designed, and their light absorption behaviors were investigated within a finite-element simulation under the substrate back-reflection, indicating that the reflection of the bottom part always works positively, while the effect of the nanocone sidewall on absorption enhancement largely depends on its geometry, arising from resonant or scattering modes. These results provide a practical guide in designing/establishing an easier/simpler way to fabricate high-performance and mechanically stable flexible nanostructured Sb 2 Se 3 thin film solar cells.

High performance is a crucial factor in seeking a more competitive levelized cost of electricity for the extensive popularization of c-Si solar cells. Here, CsPbBr 3 quantum dots (QDs) have been first applied as the light-converting layer to enhance the full-spectrum light response, resulting in an ∼71% enhancement of power conversion efficiency within silicon-based solar cells. Remarkably, even if the photon energy is smaller than the bandgap of CsPbBr 3 QDs, the long-wavelength external quantum efficiency shows a significant increase. Such surprising results can be attributed to the nonradiative energy transfer (NRET) mechanism of CsPbBr 3 QDs, which can transfer long-wavelength-generated dipoles into the Si base with the assistance of a Coulomb force. Furthermore, a dipole-transferring model, which considers that the Al 2 O 3 passivation layer would play a negative role in the NRET process, is creatively but supportively proposed. These results highlight a simple, low-cost but promising strategy to improve the performance of c-Si solar cells.

Purpose: The safety and efficacy of radical laparoscopic distal gastrectomy (LG) with D2 lymphadenectomy for the treatment of advanced gastric cancer (AGC) remain controversial. We conducted a randomized controlled trial to compare laparoscopic and conventional open distal gastrectomy with D2 lymph node dissections for AGC., Patients and Methods: Between September 2012 and December 2014, 1,056 patients with clinical stage T2-4aN0-3M0 gastric cancer were eligible for inclusion. They were randomly assigned to either the LG with D2 lymphadenectomy group (n = 528) or the open gastrectomy (OG) with D2 lymphadenectomy group (n = 528). Fifteen experienced surgeons from 14 institutions in China participated in the study. The morbidity and mortality within 30 days after surgery between the LG (n = 519) and the OG (n = 520) groups were compared on the basis of the modified intention-to-treat principle. Postoperative complications were stratified according to the Clavien-Dindo classification., Results: The compliance rates of D2 lymphadenectomy were similar between the LG and OG groups (99.4% v 99.6%; P = .845). The postoperative morbidity was 15.2% in the LG group and 12.9% in OG group with no significant difference (difference, 2.3%; 95% CI, -1.9 to 6.6; P = .285). The mortality rate was 0.4% for the LG group and zero for the OG group (difference, 0.4%; 95% CI, -0.4 to 1.4; P = .249). The distribution of severity was similar between the two groups (P = .314)., Conclusion: Experienced surgeons can safely perform LG with D2 lymphadenectomy for AGC., (© 2016 by American Society of Clinical Oncology.)