Photonic Band Gap Materials:  A little history behind Photonic Band Gap materials (PBG)? In 1987, an American physicist and engineer named Eli Yablonovitch and Canadian physics professor from the University of Toronto Canada, Sajeev John constructed artificial structures that then became the concept of PBG material. In order to evaluate this concept they created a 3D prototype diamond lattice in Plexiglas, which is a type of acrylic glass material. With this creation they were able
kinetic energy levels, which increase with the orbital radius. When atoms bond together to form a solid, the electron energy levels merge into bands. In electrical conductors, these bands are continuous but in insulators and semiconductors there is an "energy gap", in which no electron orbits can exist, between the inner valence band and outer conduction band [Book 1]. Valence electrons help to bind together the atoms in a solid by orbiting 2 adjacent nucleii, while conduction electrons, being less
Nathaniel Mackey's Bedouin Hornbook A Bedouin is a nomad and a nomad a wanderer. Nathaniel Mackey seems to wander far and away in his Bedouin Hornbook, a series of fictional letters addressed to an “Angel of Dust” and signed by the ambiguous “N.” N. interprets passages of improvisation, analyzing others’ musical expression in surprising detail to the point that his unquestioning sincerity and self-assurance are almost laughable. That N. can glean meaning from music in such a direct and certain
Thermistor Experiment Aim: To investigate how the temperature affects the resistance of a thermistor Background Information: The resistance determines the difficulty in which energy can pass through a circuit. It is measured in Ohms (Ω) and the equation for this is; Resistance (Ω) = Voltage (V) Current (I) A thermistor is a type of variable resistor that's resistance is affected by heat and in my investigation I am experimenting with the manor in which temperate affects
PHYS1002 Assignment 2 a) What materials have been used previously for PV solar cells powering space stations? [25] A Photovoltaic solar cell (PVSC) is an electrical device which converts light from the visible spectrum into direct current (DC) electricity (Honsberg). The International Space Station (ISS) originally used purified silicon solar cells for electrical generation. Silicon cells were primarily used as a result of their relatively light weight and heat conduction properties (Wittry
resorufin followed by absorption spectra were observe in order to know its progress of photocatalytic reaction. 2.4 Band gap of graphene oxide Band-gap is the difference in the energy levels between these two states of valance band (VB) and conduction band (CB). When photons of energy E≥Eb are incident on a bandgap material, a photo-generated electron is excited to the conduction band
compound, copper indium gallium diselenide (CIGS). These photovoltaic cells are built for large scale power generations. All of these semiconductors have energy band gaps between 1.1-1.7 eV. The use of Crystalline Si cells have continued to increase, but the polycrystalline has shown much more potential. Crystalline cells have an indirect band gap energy*. This results in the low optical absorption coefficient. Because of this, the wafers used in the structure needs to be greater than 200µm so that it
school football game and the marching band steps out onto the field and begins their performance, they march in very intricately choreographed paths. As viewers of the performance, we don’t see a hundred kids moving and weaving around the field. Instead we see shapes and letters in the marches. We see patterns that were choreographed by the members of the band. They know that we won’t see what each individual member of the band moving to and fro, instead we see the band as a whole and will have no trouble
Photocatalysis for water disinfection Although there are a lot of conventional water treatment methods available, but due to their disadvantages, there is a need for development of new and effective methods for disinfection of total waterborne pathogens in water treatment. In the near future, advanced oxidation process (AOPs) may become the most widely used water treatment technologies [30, 31, 32]. The processes can be categorized into three types: (1) Photolysis. (2) Homogeneous photocatalysis
His two contributions the assembly line method of factory production and the Model Ford T car greatly changed American society. Through the advent of the car, people were able to travel and bridge gaps social and economic gaps through travel and expanding communities. The assembly line allowed factories to flourish and helped to spur forward America's growth as an industrial and economic powerhouse. I would love for either my business or way I conduct my business
unknown.” Mystery can have many bone-chilling aspects in them. Mystery elements create suspense in various short stories. The short stories “Invitation to a Murder” by Josh Pachter, “Lamb to the Slaughter” by Roald Dahl and “The Adventure of the Speckled Band” by Sir Arthur Conan Doyle create suspense as a result of the mystery elements they contain. Out of all the stories, “Invitation to a Murder” stands out because invitations to law enforcements were handed out so they can witness a murder, but it also
Photonic Semiconductor Abstract- Photonic semiconductor is deeply integrated in electronic circuit designs and widely used in many sorts of applications, they act as electrical to optical or optical to electrical transducers. This paper aims to discuss various optoelectronic devices; their structure, materials, theory of operation, merit properties and characteristics that recommends them for various applications. I. Introduction Optoelectronics is a branch of Photonics Science concerns with devices
Semiconductors were being studied in laboratories as early as the 1830's. The materials were usually poor conductors if heated and often carried photoelectric properties. (Electrical production by shining light on the material.) Soon, this property of changing conductivity would become of vital importance to the world of electronics and communications. (Micron) Common semiconductors include silicon, zinc and germanium; however, silicon is by far the most widely implemented due to its abundance. Also
Performance Analysis of an Aperture Coupled Microstrip Stacked Patch Antenna For WLAN Applications Abstarct- In this paper microstrip stacked patch antenna with 10mm air gap using aperture coupling technique at frequency of 5.8 GHz has been discussed. Microstrip antennas suffer from a biggest drawback of narrow bandwidth and this can be improved by a technique called aperture coupling and further by stacking of antennas without increase in surface area of antenna. Without stacking bandwidth
Solar Energy is not a Solution to America’s Energy Crisis With the growing cost of fuel for cars and the rolling blackouts of last summer, the need for an alternative, cost-effective, environment friendly energy source is escalating. Many possible solutions have been presented, such as nuclear power, wind power, and hydrogen fuel cells; prevalent among these is solar power. Solar cells directly convert photons from the sun into electricity (Wikipedia). Solar cells that convert both solar and
when their reader is anticipating every action their character performs. Mystery elements create suspense in various short stories. In“Invitation to a Murder” by Josh Pachter, “Lamb to the Slaughter” by Roald Dahl, and “The Adventure of the Speckled Band” by Sir Arthur Conan Doyle create uncertainty as a result of the mystery elements they contain. “Invitation to a Murder” by Josh Pachter uses these elements to highlight a planned crime where a group of criminologists act as a jury for an indirect
As transistors get smaller and smaller, silicone transistors are shrinking rapidly to nearly atomic scale. As silicone transistors reach that size, it starts to become ineffective. Transistors has reached a saturation limit, where if made smaller electrons cannot be stopped from source to drain. Graphene now comes into the pictures. Graphene, is the hot topic that every physicists, material scientists, and electrical engineers have been talking about. Why did it garner such popularity in the scientific
Introduction In today’s technological culture the term Wi-Fi is omnipresent and almost every device intended to connect to the internet has corresponding hardware. In the following chapters the components of this transmission standard will be examined and the basic concepts explained. The specifications and changes to this standard are extensive and therefore only the most important aspects are considered. The information originates from the IEEE standardization committee and two independent and
extending their conjugated core or even coordinating metals or metalloids to induce a change in their conductivity and energy gap between HOMO and LUMO makes this type of molecules perfect candidates for molecular electronics. Moreover, their high molar absorption coefficients, their robustness, their tendency to act as donors and the aforementioned ability to tune their energy gap allow them to play an important role as electron donors in Organic Solar Cells. With these two branches of porphyrin applications
The five types of gaps that exist between the buyer and the seller are namely: space gap, time gap, information gap, ownership gap and value gap (Cant & Van Heerden, 2010). The space gap can be described as the actual physical distance between the manufacturer and consumer (Cant & Van Heerden, 2010). Woolworths successfully bridges the space gap by means of store numbers and locations. Most retailers, typically approach production houses, like Albany or Nestle to buy their products and re-sell them