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Nanostructured Semiconductors
Published in Sergio Pizzini, Defects in Nanocrystals, 2020
Without mentioning details of the semiconductor micro- and nano-technologies for microelectronic applications, which are outside the interests of this book, silicon nanostructures are used today in a variety of other applications, which include sensors for microfluidic systems, bio-integrated sensors [42], and high-efficiency (>18%) silicon solar cells having on the front surface a film of black silicon, consisting of an array of vertically aligned nanowires, which allow a nearly ideal absorption of the solar spectrum [43,44]. Miniaturization allowed, also, the development of solid-state optoelectronic devices on substrates consisting of compound semiconductors, and the fabrication of light-emitting diodes (LEDs), which now satisfy the conditions needed for being efficient and low-cost light sources for cars, homes, cities, and a number of battery-powered devices.
Black silicon antireflection nanostructures
Published in Klaus D. Sattler, Silicon Nanomaterials Sourcebook, 2017
Martin Steglich, Oliver Puffky
Black silicon formation during RIE of silicon in SF6–O2 chemistry relies on two chemical reactions, as well as on physical etching by impinging ions (Steglich et al. 2014). The first reaction is the etching reaction, mainly by fluorine radicals F * that form upon SF6 dissociation in the plasma:
Micro-abrasive wear study of a low-temperature plasma nitrided Inconel 625 superalloy
Published in Tribology - Materials, Surfaces & Interfaces, 2022
Luis Bernardo Varela, Michell F. C. Ordoñez, Carlos Eduardo Pinedo, Andre Paulo Tschiptschin
The microabrasion tests were performed on a commercial Anton Paar micro-scale abrasion tester with free ball configuration. The counterbody was an AISI 52100 martensitic steel sphere (25.4 mm diameter). The surface of the ball was previously conditioned by introducing it into a bottle containing abrasive slurry prepared with black silicon carbide abrasive particles and distilled water for 5 min. The abrasive slurry consisted of a suspension containing SiC particles (see Figure 1) in distilled water, with a volume fraction of 0.25 (concentration of 0.80 g.cm−3), which was continuously agitated and fed to the specimen-ball contact at a rate of one drop every 2 s. The ball rotation speed was n = 200 rpm. After this procedure, the micro-abrasive wear test was carried out. Each of the three tests was led until 100 m of sliding. The tests were performed with six different sliding distances (S), S1 = 10 m, S2 = 16 m, S3 = 25 m, S4 = 40 m, S5 = 63 m and S6 = 100 m, with an applied normal force of 0.4 N.
Properties, mechanism and applications of diamond as an antibacterial material
Published in Functional Diamond, 2022
Aude Cumont, Andrew R. Pitt, Peter A. Lambert, Marco R. Oggioni, Haitao Ye
The most investigated surface nanostructuration based on diamond films is nanospike. It was investigated after May et al. realised that black silicon nanospikes offered an incredible bactericidal effect, especially against large motile bacteria such as E. coli but had the disadvantage of being easily breakable. The addition of black diamond coating on the surface of the black silicon nanospikes allowed higher resistance to abrasion and higher hardness (Figure 10A), with a superior bactericidal property combining the physical membrane disruption of the nanospikes with the chemical effect of diamond surface functionalisation against E. coli and P. aeruginosa (Figure 10) [158, 207]. The authors also demonstrated that the space between the nanospikes (also called areal density) was of great importance to interact and disrupt the bacterial membranes and found the optimum value for E. coli and suggestions for smaller bacteria such as S. gordonii despite their smaller size, thicker membrane and lack of motility [164].
Exploring deposition pattern characteristics of aerosols and bioaerosols by inertial impaction for the development of real-time silicon MEMS mass detection systems
Published in Aerosol Science and Technology, 2021
Ugur Soysal, Evelyne Géhin, Frédéric Marty, Emmanuelle Algré, Enric Robine, Charles Motzkus
Since the first proposal of the concept of the inertial cascade impaction by (May 1945), impactors have been widely studied, used, and characterized for over 50 years. In this study, a single-stage multiple nozzle inertial impactor was designed, and it is described in detail in the online supplementary information (SI). Briefly, the impactor consists of a nozzle plate with 10 round nozzles with tapered inlets positioned circularly. The impaction chamber has a 1000 µm separation between the nozzles and the impaction plate (holder). Silicon and black silicon micro impaction plates are placed in the chamber to simulate the silicon-based MEMS mass sensor-integrated impaction conditions. Its calculated d50 is 0.39 µm and the Re is kept below 3000. Each of the 10 nozzles delivers 1 Liter per Minute (LPM) to their corresponding 10 surfaces (i.e., the 10 MEMS sensors for multi-detection). The active surface area of the sensors is 1 mm2, for reasons described elsewhere (Soysal et al., 2020). The silicon impaction plates (thickness of 500 ± 25 µm) were diced from p-type silicon wafers (Addison Engineering, Inc. San Jose, CA). This new-generation impactor enables the sampling of aerosols and bioaerosols at 10 LPM without damaging the MEMS sensors due to the divided flow. It also allows the simultaneous investigation of 10 different impaction spots.