Semiconductors or Quantum Physics (Term Paper Sample)

SEMICONDUCTORS OR QUANTUM PHYSICS
Author’s Name:
Name of the class:
Name of Professor:
Name of school:
City and state where it is located:
Date:
Introduction
Solar cells
Solar cells technology has grown over a long period of time and has proved to be beneficial to a modern man in many ways. It is from the Physics semiconductor technology that these revolutions are being created day in day out. The main mechanisms used in this technology is the use of p-n junction transistors technology. Much of this technology is arrived from the use of solid state semi-conductor materials.
Quantum Physics
Quantum Physics proved to be starling and and far reaching in the 20th Century. In this century, many scientific revolutions came up but none contributed more to the human anatomy than quantum Physics. Quantum Physics is a branch physics that deals with study of behaviour of matter at all atomic level. Its use has found many applications in many Science areas like chemistry, Cosmology, and Biology. These applications have revolutionised with the inventions like the transistor technology, and laser technology which are ushering a new era in digital technology. Figure 1. 0 shows a modern semiconductor circuit board
Figure 1.0: A modern circuit board
Light bulb technology was started by in the year 1815 by Humphrey. But in the year 1879, inventor Thomas Edison made the electrical light commercially available. Many re-inventions have been done since then including Halogen, Compact Fluorescent Light (CFL) and LEDs. There have been major developments in semiconductors and quantum physics which have led the significant transformation of live in the modern day. The physics of semiconductors have intensively been used in manufacturing electronic components and circuits. The principles of the quantum physics are widely in modern day engineering of solar cells and light bulbs
Fire as a source of light
In the documentary called ‘changing the globe’, there is evolution of quantum Physics from the time when fire used to be the source of both heat and light to a time where energy has been conserved almost to a 100% to give out only light. No energy is lost through in form of heat energy. Fats were turned into fuel in candles form but were dangerous and inefficient. Kerosene was later used to light and for heating light bulb was discovered by Thomas Edison and other 22 scientists.
Compact fluorescent lighting (CFL)
Compact fluorescent lighting (CFL) replaced these incandescent lamps. They are better since they use only 25 percent of the energy and have a life span of around times the life of incandescent lamps. However, they have mercury content which is dangerous to the environment. These lamps work by passing several electrons through mercury gas. It absorbs the energy from the electrons and UV light is produced. This light hits a phosphor coating on the glass of the tube. This phosphor glows with light that we can see. CFLs saves energy and eliminates greenhouse effects posed by previous bulbs.
Incandescent light bulbs
This bulb worked with a simple principle that it had a filament that light by pushing a number of electrons through a tungsten filament. As the speed of the electrons increases, the more the atoms gets excited. This makes the wire to glow white producing light. But in these bulbs, only 10 percent of the energy applied turned to light. In candescent lights came and phased out halogen based bulbs which are less efficient.
Light Emitting Diodes (LEDs)
To solve these problems, more innovations are being done and the moist recent one is the use of LEDs for lighting. These are made using sapphire substrate. Tiny light chips are made to grow. These chips are formed using naturally light emitting material called gallium nitride. Research is being done where this LEDS making material will have no sapphire material. The light sources will as tiny as gains of sand.
An experiment was done to examine two non-mechanical examples of energy conversion. Law of conservation of energy happens to be one of the most fundamental principles of Physics. It is known that energy can neither be created nor destroyed but can be converted from one form to another. Electrical energy in a light bulb is converted to light and heat.
The experiment carried out in this exercise examined these specific energy conversions
Experiment
Experimental procedures
A schematic diagram circuit was built as shown in figure 1.1. An ammeter was connected in series and a voltmeter in parallel.
Figure 1.1: A schematic diagram for the lab experiments
Current and voltage were measured and the power supply unplugged to avoid over heating of the bulb. A 70ml water was added to the beaker and was measured on a digital scale. The initial temperature was measured and the light bulb inserted. Power was then supplied for five minutes and was unplugged. The final temperature of water was measured and recorded. The beaker was then removed out of water and was allowed to cool for and the process was repeated for other light bulbs. In this experiment, the heat from the light bulb goes into both the water and the glass beaker
Results and observation
The following results were obtained in experiment 1: CFL (Refer to appendix for calculations)
Light Bulb:_ CFL + Clear Water

Voltage

Current

Watts

EElectrical

11.4V

0.55A

6.27watts

1881J


Ti [°C]

Tf [°C]

ΔT [°C]

ΔQwater [J]





12.2

13.8

0.7

1412.79

Experiment 2: LED in clear water
Light Bulb:_ LED + Clear Water

Voltage

Current

Watts

EElectrical

12.49

0.48

5.9952

1799J


Ti [°C]

Tf [°C]

ΔT [°C]

ΔQwater [J]

19.3

20

0.7

716.26

Experiment 3: Incandescent in clear water
Light Bulb:_ Incandescent + Clear Water

Voltage

Current

Watts

EElectrical

10.14

1.67

16.93

5080


Ti [°C]

Tf [°C]

ΔT [°C]

ΔQwater [J]

17.7

24.4

6.7

5942

Black Ink
The following results were obtained after repeating the experiment using black ink
Experiment 1: CFL in Black Ink
Light Bulb:_ CFL + Black Water

Voltage

Current

Watts

EElectrical

11.4

0.55

6.27

1881J


Ti [°C]

Tf [°C]

ΔT [°C]

ΔQwater [J]

17.2

19.9

2.7

2324.98

Experiment 2: LED in Black ink
Light Bulb:_ LED + Black Water

Voltage

Current

Watts

EElectrical

12.49

0.48

5.9952

1798J

Ti [°C]

Tf [°C]

ΔT [°C]

ΔQwater [J]

17.1

18.7

1.6

1375.22

Experiment 3: Incandescent in Black ink
Light Bulb:_ Incandescent + Black Water

Voltage

Current

Watts

EElectrical

11.4

0.55

6.27

1881J


Ti [°C]

Tf [°C]

ΔT [°C]

ΔQwater [J]

17

24.9

7.9

6325.19

Electrical energy
Energy is measured in Joules. It is defined as the ability to do work. Power is measured in watts
It is the rate at which work is done. This definition suits electrical energy. Anything that electrical energy is a load. The load used in these experiments is the automotive light bulb.
Electromagnetic spectrum
As the heat flows in the filament of the light bulb, it normally heats to a high temperature. Electrons gets excited which then occupies higher orbitals of energies. When they return to the lower energy orbitals, they emit quantum of electromagnetic energy, a photon which has a wavelength corresponding to the energy difference between the two electron states. The EM energy emitted by the tungsten filament light bulb has a UV light, a visible light and an infra-red energies. The graph shown on figure 1.2 shows an electromagnetic spectrum emitted by sun and a light bulb.
Figure 1.2: electromagnetic spectrum as emitted by the sun and a light bulb
Einstein’s Revolutionary Light–Quantum Hypothesis.
Light is an energy that is produced by an atom. According to the Einstein paper in March 1905-quantum theory of light, he explained that light is made up of the tiny packets of particles that have energy and momentum but no mass. The particles are called photon. It was also similar idea that Isaac Newton had that light is made up of tiny particles. The atoms release the light photons when their electron are been excited (Greensite, 2003, p.6). Electrons are negatively charged and move around the atoms nucleus. They do have the different level of the energy that depends on the distance from nucleus and speed. The electrons have distinct orbitals depending on the energy levels they occupy. The electron with the highest energy moves the farthest distance from the nucleus. When the atom gains or loses energy, there is a change in the movement of the particles. The electrons in this state are boosted to higher orbital where they hold this position for a while. They are then attracted back to the nucleus at the original orbitals. As the ele...