Photoresistor Research Articles

Optimizing electrical properties and efficiency of copper-doped CdS and CdTe solar cells through advanced ETL and HTL integration: a comprehensive experimental and numerical study

Abstract Copper is a commonly preferred dopant for cadmium telluride based solar cells. Even though it is widely used as it enhances the electrical properties, it has the tendency to diffuse into the CdTe layer as well as the CdS/CdTe junction interface which adversely affects the performance of CdTe solar cells. In this experimental study copper doping of buffer cadmium sulfide layer has been performed to analyse its effect on structural, electrical, and optical properties of CdS and CdTe layers. While from the X-ray diffraction analysis it was observed that there was reduction in peak intensities and crystallite sizes of both the CdS and CdTe layers with the increase in amount of copper dopant, from the electrical properties it was found that there were improvements in carrier concentration, mobility, and conductivity of both the layers. To mitigate the losses due to Cu doping, enhance the efficiency and stability of CdTe solar cells an extensive numerical modelling approach was undertaken to employ electron transport layers (ETL) and hole transport layers (HTL) to the copper-doped CdS/CdTe solar cells. We obtained optimum results with titanium dioxide and copper barium thiostannate as ETL and HTL respectively. Finally, CdTe-based solar cells were modelled integrating copper-doped CdS as the buffer layers, TiO2 as ETL and CBTS as HTL respectively. The obtained experimental values of Cu-doped CdS and CdTe layers were implemented into this model. This superstrate configuration yielded impressive output parameters: open circuit voltage of 1.07 V, short-circuit current density of 29.32 mA cm−2, fill factor of 85.08 %, and efficiency of 26.67 %.

An Assessment of Strength Characteristics of Transparent Concrete in Pavement

This study explores the potential of transparent concrete for use in roadway applications, focusing on its ability to transmit light through the incorporation of Plastic Optical Fibres (POFs) within the concrete matrix and evaluating both its mechanical strength and its light transmission capabilities. This material can be applied to various road elements, such as surface illumination, signage, roadblocks, medians, curbs, and areas with changing geometry. The light transmission performance was evaluated using voltage, light sources, and Light-Dependent Resistors (LDRs). A comparative analysis was performed between samples with varying POF content and spacing and traditional concrete. The findings reveal that compressive and flexural strengths remain largely unaffected by the inclusion of POFs up to 1.5% by weight, beyond which a decrease in strength is observed. Additionally, the light transmission efficiency improves significantly with an increase in the POF volume ratios.

Solar-Driven Agri Bot: A Storage-Free, Eco-Friendly Farming Solution

This work presents an innovative solution for sustainable agriculture by utilizing solar power to directly drive its motor system without the need for energy storage. This bot is equipped with Light Dependent Resistors (LDRs) and an Arduino microcontroller, the bot adjusts motor operations based on light conditions for optimal power efficiency. A relay switch enables seamless switching between solar power and a backup battery, ensuring continuous operation in varying sunlight. The bot’s multi-motor design supports reliable movement, accommodating a range of agricultural tasks such as transporting loads, water spraying, and ploughing. Its trolley adds versatility for carrying goods, making it practical and multifunctional in the field. This eco-friendly system not only reduces energy waste but also minimizes costs and design complexity by foregoing energy storage. Offering a cost-effective, environmentally-friendly solution for modern agriculture, this bot demonstrates a valuable application of direct solar power in field operations, supporting greener, more sustainable farming practices.

Planar Structure of Organic Photodetector for Low Dark Current

Abstract The focus of this study is on investigating the vanadyl 2,9,16,23-tetraphenoxy-29H,31H-phthalocyanine (VOPcPhO) and its blend with o-xylenyl C60 bis-adduct (OXCBA), for use as a lateral ultraviolet organic photodetector. The research focuses on improving dark current reduction, which is a challenge in lateral organic photodetector. By integrating the OXCBA, low dark current values of 4.83 nAcm-2 (D shot * = 1.414 × 1011 Jones) have been achieved as compared to the stand-alone VoPcPhO device of 14.06 nAcm-2. The major contributing factors to dark current reduction are due to the efficient charge transfer at the photoactive-electrode interface, the deep highest occupied molecular orbital (HOMO) level of OXCBA, which leads to favourable energy level alignments hindering hole injection, and the occurrence of bulk heterojunction vertical phase segregation between VOPcPhO and OXCBA. These findings shed light on the relationship between the organic photoconductor's material composition, morphology, and performance metrics and open new avenues for metal phthalocyanine-based lateral ultraviolet organic photodetectors with low dark current and enhanced performance.

Low-Cost Laser Security System with Intrusion Detection and Alert Mechanism

Security becomes necessary factor nowadays. The crime gang improves their technology to perform their operation along with the development of technology. Hence, technology of security should be more improved to protect the crime works. We have decided to make a security project. In this project we have used laser light for security purpose. We know laser light goes through long distance. When any person or object passes through the laser line, the security alarm will start to ring. There are two parts of the system. One is transmitter and other is receiver. The transmitter side consists of a pair of dry cell batteries and an on-off switch. The receiver side, there is a focusing LDR (Light Dependent Resistor) sensor to sense the laser ray. It is connected with the main driver circuit which has two parts. One is signal of discontinuity ray and other is alarm circuit. When anybody passes through the ray, the main circuit sense the discontinuity and turn on the alarm circuit. The alarm will be ringing until the off button is pressed. There are two methods of ringing. One is the duration of ringing depends on preset timer and another is reset manually. Any option can be set by DPDT switch. We have used second method for our project. Mirrors are attached at every corner to reflect the ray coming from the laser. The reflected ray coming from the last mirror will hit the LDR directly. The system has built with low cost and high performance. The power consumption of the system is very low.

AGROTECH: A Smart Agricultural System Using IOT and ML

Agriculture remains one of the most important sectors that support human survival which supplies basic needs, a source of income for many dependants' community. Despite these advantages, resource scarcity, adverse environmental conditions and pest infestations remain serious threats to crop products. To mitigate these concerns, we present a smart agriculture system which uses the most modern technologies like IoT (Internet of Things) machine learning (ML) and sensors with automation. The system consists of an intelligent irrigation mechanism for efficient utilization of water, an animal detection system used to trace cattle, and a Light Dependent Resistor (LDR) Sensor joined with buzzer for early detection of any global environmental changes. Additionally, the integration of plant disease detection capabilities further enhances the system's effectiveness. By employing various sensors to collect data on environmental factors, including moisture and temperature, the proposed framework enables timely decision-making for crop management. The aim is to provide farmers with actionable insights, ensuring food security while minimizing resource consumption and economic losses. This review paper discusses the potential benefits and implementation strategies of such an intelligent agricultural system, emphasizing the need for innovation in agricultural practices to meet the growing demands of an increasing population

Defect induced persistence photoconductivity in spray pyrolyzed ZnO thin films: Impact of Sm3+doping

The persistent photoconductivity of the rare earth ion doped ZnO is an emerging field. The present work focuses on the effect of samarium (Sm3+) ion doping on the persistence photo response behaviour ZnO host matrix. The Zn1-xSmxO (x = 0.0 to 0.10) thin films were deposited on chemically cleaned glass substrates using spray pyrolysis technique. The films showed polycrystalline nature and hexagonal wurtzite structure without any impurity peaks. The Zn0.93Sm0.07O films showed maximum crystallite size of 24.2 nm and minimum dislocation density. The gradual change in the thickness of the fibrous nature was observed with the addition of Sm3+ ions into ZnO lattice. Energy dispersive analysis of x-ray and X-ray photoelectron spectroscopy confirmed the presence of elements and its oxidation states in the deposited film respectively. The area under the curve of deconvoluted photoluminescence spectra of deposits confirmed the decrease in the various defect percentage with increase in the doping concentration of Sm3+ ions. The photoluminescence spectra of Zn0.93Sm0.07O films showed maximum near band edge emission and minimum defects. The Zn0.93Sm0.07O films showed higher carrier concentration of 1 × 1017 cm−3, mobility 32 cm2/Vs and lower resistivity of 1 × 102 Ω cm due to improved film quality. The Zn0.93Sm0.07O films exhibited the current value under dark and ultraviolet light illumination was in the range of 10−6 A and 10−4 A respectively. The maximum photocurrent was noticed at 375 nm which corresponds to the bandgap of the deposited films. The Zn0.93Sm0.07O films showed faster photo response (5 s and 131 s of response and recovery time) due to the presence of minimum trap states. Hence the Zn0.93Sm0.07O films can be used in the fabrication of light dependent resistors and ultraviolet sensors.

Design System of Solar-Powered Safety Lamp Integrated Proximity Sensor as a Solution for Accident Prevention at Blind Spot Areas

The curved contour of the road creates blind spots which increase the risk of traffic accidents. Throughout 2019, there were 107,500 accident cases recorded in Indonesia. Therefore, efforts are needed to provide road infrastructure that supports driving safety, such as traffic signs to reduce the risk of accidents in blind spot areas. This research aims to design a smart safety light warning system that is integrated with solar-based street lighting. The design uses a design-based research approach referring to several established standards including Indonesia National Standard (SNI) 7931: 2008, SNI IEC 60529:2014, Regulation of the Minister of Transportation of the Republic of Indonesia Number PM 13 of 2014, Manual on Uniform Traffic Control Devices (MUTCD) issued by the Federal Highway Administration (FHWA) of the United States Department of Transportation (USDOT), and Article 115 of Minister of Transportation Republic of Indonesia Regulation PM 27 of 2018. This study used Design-Based Research (DBR) as a research methodology. The result of this study is a prototype design and development of smart safety light warning system which can be optimized. Validation of the design and circuit is conducted using prototyping modeling 1:20 from the original dimensions to measure the function and performance of the circuit. The prototype is capable of turning on warning lights and siren notifications when detecting objects with a maximum distance of 350 cm as measured by the HC – SR04 sensor. Charging the stored solar panels via the accumulator allows the technology to continue working for 45 hours without charging. For power efficiency purposes, the technology is equipped with an LDR (Light Dependent Resistor) sensor with a minimum limit of 341-lux which regulates the lighting. The development of these safety lights will increase driver awareness when passing through blind spot areas and have positive implications for reducing the number of accidents in Indonesia.

Wearable electro-optical sensor for monitoring of nitrogen dioxide gas in environment

Environmental monitoring for detection of harmful pollutants is a challenge in today’s world. Development of wearable sensors with cost-effectiveness and practicality, while using accessible electronic components can be a solution to this challenge. In the present work ultraviolet light emitting diodes (UV-LEDs) and a Light Dependent Resistor (LDR) pair with carefully designed programmable circuitry is used to detect Nitrogen Dioxide (NO2) in the environment. The sensor is battery operated and rechargeable, making it convenient and eco-friendly. The sensor developed is miniaturized and wearable in nature for the detection of analyte gas in the environment. The sensor is stable and inexpensive as compared to the existing NO2 sensors available, which are electro-chemical, or oxide based. The sensor system is sensitive and selective to its exposure to NO2 gas and has no interference with typical environmental attributes such as humidity and temperature, which is a common challenge in gas detection technologies. The principle of gas detection is absorption based, light falling on the detector absorbed by the test gas present in the environment, thus changing the detector resistance. Absorption-based gas detection is indigenously simple but highly effective technique. This method not only ensures good sensitivity but enhances the selectivity of the electro-optical sensor towards the test gas preventing false triggering in the presence of other interfering gases.

Manipulating Photoconduction in Supramolecular Networks for Solar-Driven Nitrate Conversion to Ammonia and Oxygen.

For photoelectrodes to be used in practical catalytic applications, challenges exist in achieving the efficient production and transport of photogenerated charge-separated states. Analogous concepts in traditional inorganic photoelectrodes can be applied to their organic-polymer counterparts with improved charge-separation efficiencies. In this work, we develop photoconductive organic networks to form a high-performance photoelectrode for NO3- reduction to NH3. In the integrated network, interfaces between the organic electron-donating photoconductor and electron-accepting catalyst can generate charge carriers efficiently upon illumination, leading to enhanced charge separation for photoelectrocatalysis. The photoelectrode network is capable of converting NO3- to NH3 at an external quantum efficiency of 13%. By coupling with a BiVO4 photoanode in tandem, the system reduces NO3- to NH3 and oxidizes H2O to O2 simultaneously at Faradaic efficiencies of 95-98% with sustained photocurrents and production yields. Investigation of the photoconductive network by steady-state/time-resolved spectroscopies reveals the efficient generation and transport of free charge carriers in the photoelectrode, providing a basis for high photoelectrocatalytic performances.

Intelligent Street Lighting: An IoT-based System for Adaptive Brightness and Fault Management

The research aims to develop an intelligent fault detection and control system for street lights using an STM32 microcontroller and Internet of Things (IoT) technologies. The system uses various sensors and communication methods to manage lighting more effectively and maintain infrastructure better. Light-Dependent Resistors (LDRs), which turn lights on automatically at nightfall and off at dawn, are essential to the system's operation. Moreover, motion is detected by the infrared (IR) sensors on the street, allowing the lighting to save energy by dimming during times of low traffic and brightening when movement is detected. By using control logic and sensor readings, a relay functions as an electronically controlled switch to turn the lights on and off. To process sensor data, the STM32 microcontroller is used in the main functionality. Energy savings are facilitated by the automated on/off switching based on ambient light levels, enabled by the LDR sensor data. In addition, the device includes a GPS module for precise street light location tracking. An IoT platform transmits this location data as well as operational status and real-time sensor readings. Maintenance staff can access regional data on light quality and sensor readings through an LCD display. This extensive data enables maintenance team to focus better, use resources efficiently, and enable remote monitoring and fault identification (e.g., burned-out bulbs). This Internet-of-Things (IoT) system provides an economical and environmentally friendly approach to efficient street light management by integrating automation, remote control, and real-time monitoring.

Structure and Photocapacitance characteristics of nanosized coumarin-based dye for organic light-dependent resistor applications

The performance of a coumarin-based dye as an organic photoresistor, MACROLEX Fluorescent Red G, as an organic photoresistor was investigated. This commercial dye is highly photostable and efficiently fluorescent for solar energy applications. Specifically, this dye possesses several features, including low price, simple processing, and a high fluorescence quantum yield (90%). A comprehensive characterization was conducted using a range of techniques, such as thermogravimetric analysis (TGA), transmission electron microscopy (TEM), optical absorption, and fluorescence spectroscopy. XRD analysis revealed that the material has a polycrystalline triclinic nanostructure, The calculation of the optical band gap indicated a direct interband transition at 2.1 eV, falling within the range of semiconductor materials. Electrical conductivity and photocapacitance measurements were performed using impedance spectroscopy in the frequency range (20Hz-3MHz) at different temperatures (303–473 K). The dye-based device exhibited a significant enhancement in conductance at an illumination intensity of 100 mW cm−2, surpassing its initial value by more than 27 times. This result supports the potential application of this device as an organic light-dependent resistor (OLDR).

MOVEMENT-CONTROLLED STREET LIGHTING SYSTEM WITH MINIMAL POWER CONSUMPTION

Energy consumption in the public lighting system represents the largest part of the energy usage of a community, while the maintenance and operation of the system are a considerable expense for every city. This paper focuses on products and innovative components for street lighting, proposing a consumption-reducing solution based on an intelligent system for remote measurements and control with dimming technologies for high-intensity discharge (HID) lamps. The results indicate that considerable energy savings are achieved and the service life of the lamps is extended. A movement-controlled street light system is controlled according to the specific mode. The modes are controlled by two sensors, which are the light-dependent resistor (LDR) and the infrared (IR) sensor. This system can automatically turn on and off the lights according to traffic flow. It operates at night, and the focus is only on the one-way road at a junction. The street light will be on when there is at least one road user; otherwise, it will turn off. This design can save a great deal of energy compared to conventional street lights that keep a light throughout the night. Moreover, the maintenance cost can be reduced, and the lifespan of the system will increase. As a result, the system has been successfully designed and implemented as a model system.

Solar Panel Dirt Detection and Cleaning System

The proposed solar panel dirt detection and cleaning system improves the efficiency in generating output voltage that integrates Arduino micro-controller with voltage recognition technology to enhance the efficiency of solar energy harvesting. The system utilizes voltage divider circuit to identify dirt or debris on the solar panel surface by analyzing changes in output voltage produced by the solar panel. Along with voltage divider circuit, LDR (Light Dependent Resistor) sensor is utilized to enable the cleaning process only in day time when the intensity level of the LDR is more than threshold value. Upon detection, the Arduino micro-controller triggers a cleaning mechanism to remove the identified dirt. The cleaning mechanism can be designed using actuators, brushes and other appropriate tools. The Arduino's programmability allows for customization of cleaning intervals, ensuring timely maintenance.

Digital twin technology for enhanced smart grid performance: integrating sustainability, security, and efficiency

This research paper presents the development and analysis of a multifaceted smart grid prototype. It combines various technologies for the smart grid operation. The first technology is environmental analysis of smart grid and solar panel cleaning. Secondly, radio-frequency identification (RFID)-based security and access control system has been integrated for smart grid. The third component is internet of things (IoT)-based energy monitoring and load management. For environmental analysis sensors such as temperature, humidity, light-dependent resistor, and flame sensors are connected to a NodeMCU controller for real time monitoring. Moreover, IoT based solar cleaning system is developed in the form of prototype with the help of Blynk and servo motor. The second component of prototype is smart security system which is developed with the help of Arduino and RFID module to facilitate secure access control. The third part of prototype employs voltage and current sensors with an ESP32 microcontroller and the Blynk application for real-time energy consumption analysis. This setup enables remote monitoring of voltage, power dynamics, and consumption patterns in a smart grid. It also offers an IoT based solution for load management and load shedding within the smart grid. The complete prototype overall demonstrates a comprehensive approach to 1) smart grid management, 2) environmental analysis, 3) security, and 4) energy monitoring.

Comparative Study on Efficiency Analysis of Fixed and Dual-Axis Solar Tracking System

Solar energy is a crucial renewable energy source, offering sustainable solutions to address energy demands and combat climate change. Maximizing the efficiency of solar energy harvesting is essential for widespread adoption and integration into the energy landscape. Solar tracking systems play an important role in increasing the efficiency of solar panels by optimizing their orientation towards the sun throughout the day. This research presents a comparative analysis of the efficiency of dual-axis solar tracking systems using Light-Dependent Resistors (LDRs) as input devices. A closed-loop tracking technique is implemented to adjust the position of the solar panels based on real-time sensor feedback. A comparative study between LDRs demonstrates their effectiveness in detecting the sun's position, despite limitations such as susceptibility to ambient light conditions and saturation to light intensity. Through experimental evaluation and data analysis, this study provides valuable insights into the power output and assessment of efficiency variation of dual-axis solar tracking systems offering applications for optimizing solar energy harvesting in practical scenarios.

Microcontroller Based Automatic Street Light Control by Using LDR & IR Sensors

This project aims at designing and executing the advanced development in embedded systems for energy saving of street lights. Nowadays, human has become too busy, and is unable to find time even to switch the lights wherever not necessary. The present system is like, the street lights which will be switched on in the evening before the sun sets and they are switched off the next day morning after there is sufficient light on the roads. This paper gives the best solution for electrical power wastage. Also the manual operation of the lighting system is completely eliminated. In this the two sensors are used which are Light Dependent Resistor(LDR) sensor to indicate a day/night time and theIRsensors to detect the movement on the street. The microcontroller PIC16F877A is used as brain to control the street light system, where the programming language used for developing the software to the microcontroller is C-language. Finally, the system has been successfully designed and implemented as prototype system. Key Words: Embeded systems, Microcontroller, LDR ,IR, Lighting

An Arduino experiment to determine the gravitational acceleration using a light interruption apparatus with PLX − DAQ data acquisition tool

In this paper the author is presenting a novel experiment for measuring the gravitational acceleration using simple and cost effective apparatus with a regular pendulum, composed of an Arduino Uno and a light interruption circuit with an light dependent resistor (LDR) and an light emitting diode (LED), the data was recorded using PLX − DAQ data acquisition tool for further analysis, the experiment would be useful for introductory physics courses on the subject.

EMPOWERING FUTURE BUILDINGS WITH IOT AND 5G TECHNOLOGY

In the realm of smart buildings, the convergence of Internet of Things (IoT) and 5G technology has unlocked unprecedented opportunities for enhanced building management, efficiency, and sustainability. This project endeavors to harness the potential of IoT sensors and actuators, including LDR, DHT, gas and smoke sensors, PIR, HVAC, lights, servo motors, buzzers, and displays, integrated with Arduino Nano microcontrollers. These microcontrollers serve as end nodes, orchestrating sensor data collection and actuator control. The data collected is transmitted to a gateway device, an ESP32 microcontroller, which interfaces with a wireless Wi-Fi router for connectivity. Leveraging the ThingSpeak platform, the gateway transmits data to the cloud, facilitating real-time monitoring and analysis. This system promises to revolutionize building management by enabling remote monitoring, predictive maintenance, energy optimization, and enhanced occupant comfort and safety. Through rigorous testing and optimization, this project aims to demonstrate the feasibility and effectiveness of IoT and 5G technology integration in empowering future building infrastructures. Keywords— Heating, Ventilation, and Air Conditioning (HVAC),Light Dependent Resistor (LDR), (Digital Humidity and Temperature(DHT)

AUTOMATIC AMOUNT CALCULATION SYSTEM - SMART ENERGY METER USING IOT

In today's reality, Automatic frameworks are being favored over manual frameworks. The quick increment in the number of clients of the web over the previous decade has made the Internet an integral part of life, and IoT is the most recent and rising web innovation. Electricity is one of the fundamental necessities of human beings, it is commonly used for domestic, industrial, and agricultural purposes. These days, power theft is the main issue, costing electricity boards a lot of money and creating payment issues for customers. In our country, these situations are more often. If these thefts are prevented then a lot of power can be saved. This is done using a Smart EB meter. An energy meter chip is used in SEMs to measure the amount of electric energy used, and wireless protocols are used for data transmission. This project presents an EB meter box via automatic billing system by display. electricity continues to rise, the existing grid faces challenges related to aging infrastructure, poor visibility, and mechanical switches. Additionally, greenhouse gas emissions from the electricity industry and other stressors necessitate grid modernization. The proposed smart energy meter leverages Internet of Things (IoT) technology, enabling two-way data communication over LPWAN (Low Power Wide Area Network). These are this system's salient characteristics. The meter incorporates theft and tamper detection capabilities. Users receive notifications in case of any unauthorized interference. Key Words: Internet of Things (IoT), Light-dependent resistor (LDR), ESP8266 Microcontroller (NodeMCU), Liquid-crystal display, LoRaWAN, Energy Meter.