Comparing The And Hetero Junctions

This concept can be explained using the term band gap, a property that is characteristic of semiconductors. The band gap can be defined as the difference in energy between the valence and conduction band and is typically in the range of 1-3 eV for semiconductors. In bulk materials the energy bands are a continuum of energy levels arising from the overlapping of the atomic orbital‘s due to the large number of molecules. When a semiconductor is brought to the Nano scale, containing lesser number of molecules, the quantized energy levels become distinct. Thus the addition or removal of atoms significantly changes the energy levels within the band making the band gap size dependent.

Semiconductors are usually materials which have energy-band gaps smaller than 2eV. An important property of semiconductors is the ability to change their resistivity over several orders of magnitude by doping. Semiconductors

These boards feature capacitors, transformers, internal circuits, and ports such as DVI and VGA, most of which were created in New Taipei, Taiwan. The board on the top left processes the commands inputted through the keyboard and mouse, while the one on the bottom controls the visual display the commands inputted into the computer through typing or mouse movement. The board on the top right processes and interprets data from external drives and disks. Each of these cards contain capacitors, internal circuits, and diodes, which are all necessary components in the monitor to help the boards function properly. The internal circuit on the bottom motherboard, as well as other smaller circuits, were developed by HannStar in their Nanjing corporation located in Nanjing, China. The board on the top right, which is a LCD monitor controller, contains a specific integrated circuit designed by Genesis Microchip Incorporated that uses a serial flash interface to achieve peak pin count efficiency including error calculators known as derivatives controllers giving consumers the ability to find parts of the monitor with a singular process control block (PCB). Unisonic Technologies Co. Ltd developed several of the internal circuits in these boards including a circuit manufactured by Texas Instruments. One of the chips with the product number TDA7496 is a 4-watt class AB power amplifier which was designed for specifically for high-quality sound, meant to be

Semiconductors allow the flow of both ions and electrons through the sample but not completely free; and its

As the outermost electrons can move freely around the atomic structure of the metallic bond, it won’t matter what potential difference is used as the electric current could enter through the metal. Most importantly, this unknown substance must be a metallic bond due to its malleability property – all metals can be pressed permanently or hammered out of shape

It is easier for it to lose electrons than it is for Br, this is because Br has the same atomic radius (115 pm) as does Se, but Br more protons to hold its electrons from being taken, & itso has a stronger pull for its own electrons and greater than that of tellurium. Se has a strong hold on its electrons, because it is a smaller atom than Te, with Te's valence electrons further out the strength with which they are held falls off by the square with distance. Te has a radius of 140 pm compared to Br's of 115 pm.

“The photovoltaic effect is the basic physical process through which a photovoltaic cell converts sunlight into electricity.”(Seale E, 2003) Sunlight is composed of photons, the photons contain various amounts of energy corresponding to different wavelengths of light. When the light strikes the photovoltaic cell, it will be reflected, absorbed or pass through the two side photovoltaic cell. One side has a positive electric charge while the other side has a negative charge. Light striking crystals such as silicon or germanium, in which electrons are usually not free to move from atom to atom within the crystal,

Enhancing the ability of a semiconductor to conduct electricity by adding small amount of certain impurities to the element.

As part of our major project we are required to show our knowledge and understanding of at least 2 major materials or components that we may be using in our project. The 2 components which I’ve decided to work on are resistors and LDR (light depended resistor). I will be discussing about the many functions and uses of these components which makes them a major component for our project.

Capacitance-voltage (C-V) characterization is a non-destructive technique which determines the charge distribution and identifies the presence of interface states in semiconductors when the applied biasing voltage participates in the carrier capture and emission at interface traps [14,15]. Such traps are charged leading to the production of a dipole layer at the interface. Small modulation in the AC bias will change the barrier height, and the position of the Fermi level will shift relative to its equilibrium position. Thus, the characteristics of the device will be changed [15,16].

Since their discovery in the early 1990s, there has been intense activity exploring the electrical properties of these systems and their potential applications in electronics.

Electronegativity increases from bottom to top in a periodic table. P1.00 has the highest electronegativity (smallest atomic radius) as a result it has the largest band gap energy. The above data shows as the size decreases ( EN increases) the band gap energy increases.

The band theory gives explanations of how Semiconductors differ from metals because as the temperature increases the conductivity increases. The Band Theory considers that for

Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference or voltage across the two points, and inversely proportional to the resistance between them provided the temperature remains constant.

We have now discussed the two extremes in electronic materials; a conductor, and an insulator we will now move to a material that lies in between these two, a semiconductor. The