Optimization and Development of ITO-Free Plasmonic Gold Nanoparticles Assisted Inverted Organic Solar Cells

This paper focuses on the fabrication of an ITO-free plasmonic assisted inverted organic solar cell (OSC) constituting aluminium doped zinc oxide (AZO) as front cathode and ultraviolet (UV) filtering layer. The gold nanoflowers are introduced in the device to increase the efficiency using localized surface plasmon resonance (LSPR) shown by plasmonic nanoparticles. We used GPVDM software to first optimize the cell, based on the geometry AZO/ZnO/PTB7:PC71BM/MoO3/Ag where AZO acts as the transparent conducting oxide (TCO) cathode and UV filter, zinc oxide (ZnO) behaves as the electron transport layer (ETL), Thieno[3,4 b]thiophene-alt-benzodithiophene: [6,6]-phenyl C71 butyric acid methyl ester (PTB7: PC71BM) mixture as the active layer, molybdenum trioxide (MoO3) as the hole transport layer (HTL) and silver (Ag) serves as the anode layer. By modelling, we find that the optimized device with maximum power conversion efficiency (PCE) includes 10 nm thick HTL, 200 nm thick photoactive layer and ETL thickness of 30 nm. Using the optimized thicknesses, we have fabricated three structurally identical inverted OSCs: first having AZO as the front cathode (AZO based device); second with ITO as the front cathode (ITO based control device); third includes AZO as cathode and plasmonic gold nanoflowers embedded inside the active layer (plasmonic assisted AZO based device). The AZO based device exhibited the PCE value of 6.19%, slightly less than the efficiency of 6.83% for ITO based control device. However, a remarkable increase in the lifetime was achieved for AZO based device under UV assisted acceleration ageing test. The stability enhancement of AZO based device is because of the UV filtering properties of AZO which prevent degradation in the device due to UV exposure. Also, the PCE of AZO based device was further enhanced to 7.01% when plasmonic gold nanoparticles were included in the active layer. This work provides a feasible way to develop an ITO free plasmonic assisted inverted organic solar cell to achieve cost-effectiveness, high efficiency and stability.

Controllable shifting, steering, and expanding of light beam based on multi-layer liquid-crystal cells

Shaping and steering of light beams is essential in many modern applications, ranging from optical tweezers, camera lenses, vision correction to 3D displays. However, current realisations require increasingly greater tunability and aim for lesser specificity for use in diverse applications. Here, we demonstrate tunable light beam control based on multi-layer liquid-crystal cells and external electric field, capable of extended beam shifting, steering, and expanding, using a combination of theory and full numerical modelling, both for liquid crystal orientations and the transmitted light. Specifically, by exploiting three different function-specific and tunable birefringent nematic layers, we show an effective liquid-crystal beam control device, capable of precise control of outgoing light propagation, with possible application in projectors or automotive headlamps.

Ultra-fast data sanitization of SRAM by back-biasing to resist a cold boot attack

Although SRAM is a well-established type of volatile memory, data remanence has been observed at low temperature even for a power-off state, and thus it is vulnerable to a physical cold boot attack. To address this, an ultra-fast data sanitization method within 5 ns is demonstrated with physics-based simulations for avoidance of the cold boot attack to SRAM. Back-bias, which can control device parameters of CMOS, such as threshold voltage and leakage current, was utilized for the ultra-fast data sanitization. It is applicable to temporary erasing with data recoverability against a low-level attack as well as permanent erasing with data irrecoverability against a high-level attack.

Printed in-plane electrolyte-gated transistor based on zinc oxide

Printed electronics is a reputable research area that encourages the search for simple alternatives of manufacturing processes for low-cost, eco-friendly, and biodegradable electronic devices. Among these devices, electrolyte-gated transistors (EGTs) stand out due to their simple manufacturing process and architecture. Here we report the study of printed electrolyte-gated transistors with in-plane gate architecture (IPGT) based on zinc oxide nanoparticles (ZnO-NPs). The drain, source, and gate electrodes with two different W/L channel ratios were fabricated using a screen-printed carbon-based ink. We also produced a conventional top-gate transistor as a control device, using the same structure as the IPGT described above by adding an ITO strip positioned over the electrolyte as the top-gate electrode. The IPGT with W/L = 5 presented a high mobility of 7.1 cm2V-1s-1, while the W/L = 2.5 device exhibited a mobility of 3.7 cm2V-1s-1. We found that the measured field-effect mobility of the device can be affected by the high contact resistance from the carbon electrodes. This effect could be observed when the geometric parameters of the devices were changed. Furthermore, we also found that the IPGT with W/L = 5 exhibited better values for mobility and transconductance than the top-gate transistor, showing that the IPGTs setup is a good promise for cheap and printed transistors with performance comparable to standard top-gate transistors.

Neuroevolutionary reinforcing learning of neural networks

The article presents the results of combining 4 different types of neural network learning: evolutionary, reinforcing, deep and extrapolating. The last two are used as the primary method for reducing the dimension of the input signal of the system and simplifying the process of its training in terms of computational complexity.In the presented work, the neural network structure of the control device of the modeled system is formed in the course of the evolutionary process, taking into account the currently known structural and developmental features of self-learning systems that take place in living nature. This method of constructing it makes it possible to bypass the specific limitations of models created on the basis of recombination of already known topologies of neural networks.

Bluetooth-Tracing RSSI Sampling Method as Basic Technology of Indoor Localization for Smart Grid

In recent years, Smart Grid have become the center of interest for IT companies and construction companies and various types of Smart Grids have been made currently available on the market. Yet, equipment is costly and it is not easy to convert existing equipment for Smart Grid application as they may require additional resources which could also inflict much costs. The extra costs involving the remodeling of existing housing structure and installment of new equipment can be avoided by using advanced wireless technologies. As an example, this book proposed an indoor localization system that adopts Bluetooth technology and uses RSSI (Received Signal Strength Indication) values for localization. Researchers have configured a system where the central control device will recognize all other devices or equipment in the system, communicate with each other, and respond to the commands or the information provided. However, despite the efforts of many researchers, existing RSSI-based indoor localization systems do not show a satisfactory level of accuracy such that we have devised a system that traces the trend in the RSSI samples.

APPLICATION OF THREE-DIMENSIONAL MODELING TO OPTIMIZE THE DIMENTIONS OF THE SPEED CONTROL DEVICE WITH ROTARY STOPPER IN THE FORM OF A CLOSED-LOOP HYDRAULIC SYSTEM

The aim of this work is to create a three-dimensional model of a new speed change control device using an engineering CAD system Solidworks. In particular, the article describes the methods of computer construction of a three-dimensional model of a rotary stopper in the form of a closed-loop hydraulic system of the device for smooth control of speed changes through a gear differential. The control link can be either a ring gear, or a carrier, or a sun gear. Ways of creating new parts of the device, use of elements from standard libraries and coordination of their dimensions in assembly have been considered. The ability to parameterize the dimensions allows you to automate the creation of both a single part and the whole device of a particular design, based on the specified source data. The application of special meshes for modeling movable and fixed joints allows you to correctly place the parts, control the correctness of their assembly, and then conduct kinematic and power studies of the device, animate its elements in motion. It has been concluded that the use of computer three-dimensional modeling in the design of such stoppers allows: at the initial stage of design to get a visual idea of the stopper of rotational motion; use a computer to view the created model from any point; easy to edit three-dimensional models, i.e. make the necessary changes; achieve great savings in time and design costs; get a large number of possible design solutions that need to be analyzed in detail and in depth to choose the rational, i.e. the best fit. The created model of the stopper of rotational movement allows to choose the optimal place of its installation in a gear differential of the device of speed change from the point of view of use of the minimum sizes and volume. Based on this, computer simulation must precede design. Keywords: three-dimensional modeling; rotary stopper; closed-loop hydraulic system; gear differential