Abstract- this paper presents OLEDs (Organic Light Emitting Diodes).How they work, what they are prepared of, and different policies to manufacture them with layers thicknesses, and the many functions for them. OLEDs function as both light source and color array at the same time; they are used to generate digital displays in devices. Due to their early stage of improvement, they normally release fewer lights per unit area than inorganic solid-state based LED point-light sources. Introduction-An OLED (organic light-emitting diode) is a sort of LED (light-emitting diode), where the emissive electroluminescent level is a film of organic compound which releases light in response to an electric current. This layer of organic semiconductor material…
Both unipolar and bipolar PWM [41] can be employed. FBHSC modulation scheme is the same as the conventional FB inverter, only with addition of the modulation signal to additional switches. The proposed topology has only four conduction states, which are presented in Fig. 3. MOSFET on-resistance Ron is necessary to limit the instantaneous current when two capacitors are connected in parallel (e.g. in Fig. 3c). Seeing that, MOSFET is the preferred switch to realize the proposed converter, due to…
Full-wave rectifier converts whole of AC cycle into pulsating DC while half-wave rectifier converts only one-half of AC cycle into pulsating DC. Moreover, the half-wave rectifier is unidirectional so, it only allows the conduction in one direction which means either it only can convert positive half or negative half into DC voltage while the full-wave is bi-directional so, it can convert positive half and negative half of the cycle into DC voltage. Two networks that perform full-wave…
Current semiconductor lasers can also produce visible light, with red being the least expensive type of semiconductor laser and green, blue, and violet being increasingly more expensive. Semiconductor lasers used in laser pointers are also known as diode lasers, because they are a type of semiconductor diode. A diode passes electricity easily in one direction; light emitting diodes and laser diodes produce light when electricity passes through them. Semiconductor electronics have become less…
Semiconductor devices have transformed the way that we live by making tasks easier and more efficient than before. By utilizing the opinions of different professionals in the field about their affect on society, I want to investigate the different aspects of semiconductor devices. The question of will the accumulation of both the positive and negative outputs of the semiconductor industry lead to the need of advancing technology that is independent of the semiconductor. This is important to me…
relation when using the tachometer, it shows you how fast your engine is rotating and tells you when to shift the gears if it’s a manual transmission car. They are many different types of display used in vehicles. The first is vacuum fluorescent, which uses tubes that are filled with argon or neon gases and when electrical current passes through the tubes it creates a bright and durable light. The next is heads up display with uses the parts from the vacuum fluorescent system. The HUD works by…
In this study, the effect of benzenethiol ligand on CdSe/ZnS core/shell quantum dots was investigated. Conventional long-chain oleic acid (OA) and trioctylphosphine (TOP) capping ligands were partially replaced by short benzenethiol ligands, and the improvement in the luminescence performance was observed in quantum dot light emitting diodes (QD-LED). Approximately 1.8 fold improvement was achieved for both the maximum luminance and maximum current efficiency for the QD-LEDs fabricated with…
The emitters and photo detector are placed so as to face each other through tissue about 5-10 mm in thickness. The diodes are switched turn on and turn off in rapid sequence so that each measurement set include an estimate of transmission of infrared light, red light and ambient illumination. The ratio of red to infrared light is determined and the corresponding oxyhemoglobin saturation is found from an empirically determined table. The individual measurements are made each second and fed into…
Keywords: Visible Light Communication (VLC), Light Fidelity (Li-Fi), Wireless Data Communication, I. INTRODUCTION The Visible Light Communication (VLC) is a recent technology that uses light instead of radio frequency signals to transmit the data. It is also known as short-range optical wireless communication. Prof. Harald Haas introduced Light Fidelity (Li-Fi) which resolves the issue of overuse of radio frequency in Wi-Fi [1] [7]. The objective of VLC is to increase data rates in…
Table-2 shows the expected power saving after making comparison between usage of LED and HPS lamps. From this calculation, comparison in term of energy efficiency is obtained between High Pressure Sodium (HPS), type of lamps which is commonly used in public street lighting with Light Emitting Diode (LED) for automation system which operate according traffic flow by sensing the movement within certain time. The comparison with other LED is also made, which used for public street lighting that…