Light Emitting Diodes Semiconductor

Materials for Optics (LCDS, LEDs)?

What kinds of materials are used, and how do they create the image that we see (diagrams are nice)? Are there any equations that I should know?

I'm talking of course, about liquid crystal display (smectic and nematic liquid crystals), and semiconductor light emitting diodes.
something not from wikipedia or something that can't be easily googled would be good

i need good sources
preferably something from a university that is understandable and not overly complex for a chem student

Liquid Crystal

http://en.wikipedia.org/wiki/Liquid_crystal

LCDs

http://en.wikipedia.org/wiki/Lcd

LEDs

http://en.wikipedia.org/wiki/LED

Other display technologies

OLEDs

http://en.wikipedia.org/wiki/Organic_light-emitting_diode

Plasma

http://en.wikipedia.org/wiki/Plasma_display

ELDs

http://en.wikipedia.org/wiki/Electroluminescent_display

SEDs

http://en.wikipedia.org/wiki/Surface-conduction_electron-emitter_display

FEDs

http://en.wikipedia.org/wiki/Field_emission_display

Introduction to Nitride Semiconductor Blue Lasers and Light Emitting Diodes $204.7 No Synopsis Available

Light-Emitting Diodes (Hardcover) $186.1 Revised and fully up-dated, the second edition of this graduate textbook offers a comprehensive explanation of the technology and physics of LEDs such as infrared, visible-spectrum, ultraviolet, and white LEDs made from III-V semiconductors. Elementary properties such as electrical and optical characteristics are reviewed, followed by the analysis of advanced device structures. With nine additional chapters, the treatment of LEDs has been vastly expanded, including new material on device packaging, reflectors, UV LEDs, III-V nitride materials, solid-state sources for illumination applications, and junction temperature. Radiative and non-radiative recombination dynamics, methods for improving light extraction, high-efficiency and high-power device designs, white-light emitters with wavelength-converting phosphor materials, optical reflectors, and spontaneous recombination in resonant-cavity structures are discussed in detail. With exercises, solutions, and illustrative examples, this textbook will be of interest to scientists and engineers working on LEDs and graduate students in electrical engineering, applied physics, and materials science.

Light-Emitting Diodes $87.75 No Synopsis Available

Organic Light Emitting Diodes (Hardcover) $385.4 Addressing the development of the organic light emitting diode (OLED) based on rare-earth and transition-metal complexes—Europium, Terbium, Ruthenium, and Rhenium—this unique perspective explains how these materials can be used to build organic-LEDs, from chemistry synthesis to device operation and the related charge transfer and confinement. Examining how organic materials can be used to build organic-LEDs, the relationship between the chemistry molecule "design," and state-of-the-art and expected pathways, this intelligent report provides intensive experimental results for scientists and engineers working in this new OLED framework, while maintaining a didactic utility for graduation students and teachers studying optoelectronics.

Polymer Light Emitting Diodes Based on Polyfluorenes $138.61 This work is devoted to the study on Polymer Light Emitting Diodes (PLEDs) based on polyfluorenes, a promising class of semiconductive polymers for lightemitting diode applications. It covers theories of PLEDs, literature overview of polyfluorenebased lightemitting diodes, as well as research results by the authors. In this study, several types of PLED devices based on neat polyfluorenes or polyfluorene blends were designed, fabricated, and characterized. The electrical characteristics of two neat polyfluorenes were simulated via using space charge limited current theory for the holeonly case and/or exploiting a commercial software package. Author: Zhang, Qiushu/ Zivanovic, Sandra Binding Type: Paperback Number of Pages: 164 Publication Date: 2010/08/16 Language: English Dimensions: 5.98 x 9.01 x 0.37 inches

Light-emitting Diodes and Optoelectronics (Hardcover) $369.61 Description not available.

Electroluminescence in Organic Light-emitting Diodes $80.93 No Synopsis Available

Blue Laser and Light Emitting Diodes II $95.55 No Synopsis Available

Organic Light-Emitting Diodes: Principles, Characteristics & Processes $233.95 No Synopsis Available

Principles of Solar Cells, Leds and Diodes (Hardcover) $364.39 The book will cover the two most important applications of semiconductor diodes – solar cells and LEDs - together with quantitative coverage of the physics of the PN junction at the senior undergraduate level. It will include: Review of semiconductor physicsIntroduction to PN diodesThe solar cellPhysics of efficient conversion of sunlight into electrical energy  Semiconductor solar cell materials and device physicsAdvanced solar cell materials and devicesThe light emitting diodePhysics of efficient conversion of electrical energy into lightSemiconductor light emitting diode materials  and device physicsAdvanced light emitting diode materials and devices

Principles of Solar Cells, Leds and Diodes (Paperback) $148.45 The book will cover the two most important applications of semiconductor diodes – solar cells and LEDs - together with quantitative coverage of the physics of the PN junction at the senior undergraduate level. It will include: Review of semiconductor physicsIntroduction to PN diodesThe solar cellPhysics of efficient conversion of sunlight into electrical energy  Semiconductor solar cell materials and device physicsAdvanced solar cell materials and devicesThe light emitting diodePhysics of efficient conversion of electrical energy into lightSemiconductor light emitting diode materials  and device physicsAdvanced light emitting diode materials and devices

Organic Light Emitting Diodes : The Use of Rare Earth and Transition Metals $146.2 No Synopsis Available

CarbazoleBased Emitting Compounds $141.79 Carbazole is a heterocyclic tricyclic aromatic organic compound consisting of two sixmembered benzene rings fused on either side of a fivemembered nitrogencontaining ring. A large number of carbazole derivatives have been designed and synthesized and organic electronic devices based on these derivatives such as organic light emitting diodes (OLEDs), have been investigated. The optical and electrical properties of carbazoles are affected by substitution on the 2, 3, 6, 7 and 9Hpositions. Many carbazole derivatives have sufficiently high triplet energy to make them an efficient host where they can serve as red, green, or blue triplet emitters. Highly fluorescent and stable carbazolebased compounds were synthesized and characterized. Substitution of carbazoles at 3 and 6 position by tertbutyl group enhanced the solubility. Suitably susbtituted carbazoles form highly stable fluorescent organic nanoparticles. The emission of these nanoparticles was reversibly switched on/off in the bluegreen and orangered regions from a change in the ratio of the tetrahydrofuran/water system used in their preparation. Author: Adhikari, Ravi/ Neckers, Dr Douglas C. Binding Type: Paperback Number of Pages: 192 Publication Date: 2010/05/05 Language: English Dimensions: 5.98 x 9.01 x 0.44 inches

Fundamentals of High-Efficiency OLEDS: Basic Science to Manufacturing of Organic Light-Emitting Diodes $126.7 No Synopsis Available

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Semiconductor Diodes?

1. A diode characteristic curve is a plot between
[a] current and time
[b] voltage and time
[c] voltage and current
[d] forward voltage and reverse voltage
2. The colour of light emitted by a LED depends upon
[a] its forward bias
[b] its reverse bias
[c] the amount of forward current
[d] the type of semiconductor material used
3. In a half-wave rectifier, the diode conducts during
[a] both halves of the input cycle
[b] a portion of the positive half of the input cycle
[c] a portion of the negative half of the input cycle
[d] one half of the input cycle
Can you also explain briefly how u chose the answer for each question?
Thanks!

1) The diode IV characteristic is given by:

Id = Is (e^(Vbe/Vt) - 1),

where: Id is the diode current and Vbe is the base-emiiter
voltage.

Therefore, c) is the correct choice.

2) The correct choice is d). The type of semiconductor
diode used determines the color of light emitted. Since, different materials have different bandgap energies and this determines the color
of light emitted by the LED.

3) The correct choice is d) 1/2 of the input cycle.

Since the diode is forward-biased in the positive
1/2 of the input waveform and in the negative half cycle
of the waveform the diode is reverse-biased and is
therefore in the blocking state.