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In this research work, the tungsten diselenide (WSe2)-based thin-film solar cell with a copper thiocyanate (CuSCN) hole transport layer (HTL) has been designed and studied by using the Solar Cell Capacitance Simulator in One Dimension software program (SCAPS-1D). A comparative numerical study between Al/ITO/CdS/WSe2/Ni and Al/ITO/CdS/WSe2/CuSCN/Ni has been done. The SCAPS-1D simulator has been utilized to investigate photovoltaic parameters such as open circuit voltage, short-circuit current density, fill-factor, power conversion efficiency and quantum efficiency of heterojunction solar cell due to the variation of thickness, doping density, bulk defect density, defect density at buffer/absorber and absorber/HTL interfaces, operating temperature, band alignment and back surface recombination velocity. The conversion efficiency of 17.33% has been determined for the WSe2 solar cell without HTL. On the contrary, the efficiency of the proposed solar cell with CuSCN HTL has been found to be 24.20% at the optimal device structure. These numerical findings of the present study may therefore provide an intuitive approach to fabricate an economically feasible and highly efficient WSe2-based heterojunction thin-film solar cell.

We have Developed an IoT-based real-time solar power monitoring system in this paper. It seeks an opensource IoT solution that can collect real-time data and continuously monitor the power output and environmental conditions of a photovoltaic panel.The Objective of this work is to continuously monitor the status of various parameters associated with solar systems through sensors without visiting manually, saving time and ensures efficient power output from PV panels while monitoring for faulty solar panels, weather conditionsand other such issues that affect solar effectiveness.Manually, the user must use a multimeter to determine what value of measurement of the system is appropriate for appliance consumers, which is difficult for the larger System. But the Solar Energy Monitoring system is designed to make it easier for users to use the solar system.This system is comprised of a microcontroller (Node MCU), a PV panel, sensors (INA219 Current Module, Digital Temperature Sensor, LDR), a Battery Charger Module, and a battery. The data from the PV panels and other appliances are sent to the cloud (Thingspeak) via the internet using IoT technology and a Wi-Fi module (NodeMCU). It also allows users in remote areas to monitor the parameters of the solar power plant using connected devices. The user can view the current, previous, and average parameters of the solar PV system, such as voltage, current, temperature, and light intensity using a Graphical User Interface. This will facilitate fault detection and maintenance of the solar power plant easier and saves time.

This paper presents the development of a sensor based smart irrigation system with the capabilities of remote monitoring and controlling of water usage in the agriculture field using Internet of Things (IoT). With the employment of IoT in irrigation system, all agricultural information can be viewed and controlled at the user's fingertips. The system consists of a microcontroller (Node MCU), sensors (soil moisture, DHT11), and irrigation of a water pump with a decision-making system. Sensors are linked to a Wi-Fi module (Node MCU) and are interdependent to provide increased sensitivity to the irrigation system. The data obtained will be uploaded to the cloud (ThingSpeak) and presented in the form of graphs accessible via the website. A web page is used to control the water pump for irrigation purposes. This paper is managed to meet all of its aims to help farmers in terms of time, project cost, labor, water consumption, power consumption, and reliability by implementing the IoT-based smart irrigation system.

The bit error rate performance of a V-Blast encoded 8x8 MIMO MC-CDMA wireless communication system for different signal detection (MMSE and ZF) and digital modulation (BPSK, QPSK, DPSK, and 4QAM) schemes for grayscale image transmission has been investigated in this paper. The proposed wireless system employ ½-rated Convolution and cyclic redundancy check (CRC) channel encoding over the AWGN channel and Walsh Hadamard code as an orthogonal spread code. The present Matlab based simulation study demonstrates that the V-Blast encoded 8×8 MIMO MC-CDMA wireless system with the employment of 1⁄2- rated convolution and cyclic redundancy check (CRC) channel encoding strategies shows good performance utilizing BPSK digital modulation and ZF signal detection scheme in grayscale image transmission.

Energy consumption is a significant issue for data forwarding in Delay-Tolerant Network (DTN), where nodes are energy-constrained as they are driven by batteries. During their limited lifetime, these nodes have to spend a huge amount of energy since they perform forwarding, receiving, and temporarily storing messages, searching for the neighboring nodes for message forwarding, etc. The remaining energy of a node is expected to be higher as it increases the possibility of successful message delivery. Hence, awareness of energy expenditure is necessary for the routing strategies in DTN. This issue instigated us to evaluate the impact of node remaining energy on social-based routing protocols for the DTN scenario. Apart from the conventional DTN forwarding techniques, social-based forwarding protocols have involved an emerging concept that considers nodes’ social relations and behaviors to make routing decisions for efficient message transmission. In this paper, we have analyzed the energy efficiency of several social-based routing approaches, such as Social-aware Content-based Opportunistic Routing Protocol (SCORP), dLife, dLifeComm, and Bubble Rap with their corresponding performance evaluations regarding the performance metrics: average remaining energy, delivery ratio, average delay, and transmission cost. Opportunistic Network Environment (ONE) simulator is used as the simulation tool, where all the simulations are performed by (i) varying the number of nodes in each group with a fixed message Time-To-Live (TTL), and (ii) changing the message TTL, while the number of nodes per group is kept constant. From the outcome of simulations, it is observed that SCORP has the highest energy efficiency and shows the best performances for average delay and transmission cost.

Delay-Tolerant Network (DTN) is a resource-bound networking system which consists of many intermittently connected, movable devices known as nodes. Energy can be considered as an important resource for DTN scenarios since these nodes have limited energy. In order to perfect network enforcement, it is necessary to exploit the energy of the nodes efficiently. In DTN, most of the node energy is consumed because of mobility, scanning neighbors to deliver message and message transmission. Node energy has a significant role for successful transmission of messages. Higher energy of a node means that it has a high possibility to route its message with success across the network. So, for effective message routing it is mandatory to select an energy efficient routing mechanism in DTN environment. This point makes us interested to study the consumption of node energy in DTN scenarios. Within this research, the study of energy issue is focused for DTN routing approaches: Epidemic, Resource Allocation Protocol for Intentional DTN (RAPID), MaxProp, Probabilistic Routing Protocol using History of Encounters and Transitivity (PRoPHET), Spray and Wait, and Spray and Focus with their comparative performance analysis on behalf of four performance criteria: average remaining energy of node, delivery ratio, average latency, and transmission cost. Simulations are performed in Opportunistic Network Environment (ONE) simulator by varying node density while keeping message Time-To-Live (TTL) fixed and further, message TTL is changed while node density is kept fixed. We have found that Spray and Wait is the most energy efficient DTN routing scheme, whereas Spray and Focus yields the best performance in terms of delivery ratio, average latency and transmission cost.

We have developed an optical method of detecting and characterizing nonradiative recombination (NRR) centers without electrical contact. The method combines a below-gap excitation (BGE) light with a conventional above-gap excitation light in photoluminescence (PL) measurement, and discriminates the PL intensity change due to switching on and off the BGE. A quantitative analysis of the detected NRR centers became possible by utilizing the saturating tendency of the PL intensity change with increasing the BGE density due to trap filling effect. Some experimental results of AlGaAs, InGaN, and AlGaN quantum wells were shown to allocate the development and present status as well as to exemplify their interpretations.