The physics of solar cells jennynelson, 2008 aband structur for ndoped and pdoped principle of solar cell. Conversion of light energy in electrical energy is based on a phenomenon called photovoltaic effect. Fundamental properties of solar cells, principles and. Basic principles and measurements dyesensitized solar cell dssc, dsc or dysc1 is a lowcost solar cell belonging to the group of thin film solar cells. Solar power and solar panels are getting a lot of attention as part of the solution to our energy crisis. A solar panel consists of numbers of solar cells connected in series or parallel. Solar cells from light to electricity solar impulse. Critical factors that affecting efficiency of solar cells. Solar cells are used on spaceships like the international space station pictured below, but are also used on earth in places that get lots of sunlight throughout the year.
Solar energy, also called photovoltaic energy, is undergoing rapid changes thanks to massive investment in research and development. When semiconductor materials are exposed to light, the some of the photons of light ray are absorbed by the semiconductor crystal which causes a significant number of free electrons in the crystal. Principle of solar cell about solar energy our solar. An external load can be powered when light shines on the anode of the dye solar cell. The theory of solar cells explains the process by which light energy in photons is converted into electric current when the photons strike a suitable semiconductor device. How a photovoltaic cell works from silicon to electricity. The above efficiency example corresponds to the previous listing of solar cell. Utilizing nanotechnology in inexpensive solar cell would help to preserve the environment. When solar cells absorb sunlight, free electrons and holes are created at positivenegative junctions. The following section describes all relevant electrochemical processes. Light photon energy electric energy silicon solar photovoltaic cells a device made of semiconductor materials that produce electricity under light a pn junction is created in silicon by a doping process. Solar cell, also called photovoltaic cell, any device that directly converts the energy of light into electrical energy through the photovoltaic effect. Each of the above cell types has a peak efficiency as seen in the below example.
The basic principle behind the function of solar cell is based on photovoltaic effect. The number of solar cell connected in a series generates the desired output. A physical barrier is created between them along the pn junction, with electrons and holes diffusing into regions of. The amorphous word with respect to solar cell means that the comprising silicon material of the cell lacks a definite arrangement of atoms in the lattice, noncrystalline structure, or. Many different solar cell technologies are being developed, for various applications rooftops, solar power plants, satellites, backpacks or clothing, etc. The solar cell is a semi conductor device, which converts the solar energy into electrical energy. This is the basic reason for producing electricity due to photovoltaic effect. The nanostructured wide bandgap oxide semiconductor electron acceptor is applied, printed or grown on the conductive side. More generally such ultra thin buffer layer improves the solar cells performances. The physics of solar cells jennynelson, 2008 f1r principle of solar cell pn. A solar cell is basically a junction diode, although its construction it is little bit different from conventional pn junction diodes.
As long as there is sufficient light these calculators seem to be able to keep working. Application of pn junctions within solar cells is discussed. The working principle of solar cells is based on the photovoltaic effect, i. An important source for renewable energy is solar power and manufacturing dscs is simple, due to low cost, and the ability to incorporate environmentally friendly materials. Principle of a dye solar cell as the name implies, the mechanism of dye solar cells is based on the photo electrochemical processes. The theoretical studies are of practical use because they predict the fundamental limits of a solar cell, and give guidance on the phenomena that contribute to losses and solar cell efficiency. The first solid state perovskite solar cell, which employs solid organic semiconductor as htl showed improved stability and better performance of 10.
A complete bulk heterojunction organic solar cell is pictured in figure 5. On the base of the slab a small amount of a p dopant, typically boron, is diffused. We give the upper limit to the solar cell e ciency. Therefore, asi amorphous solar cell is comparatively cheaper and widely available. The solar cell traps all the electrons released by the silicon and pushes them in one direction, which creates an electric current. Ch4 solar cell operational principles tu delft ocw. Schematic of the structure of the dye sensitized solar cell. Denis ar con ljubljana, may 2011 abstract this seminar is a short overview of current photovoltaics. The ability of a cell to convert the maximum amount of light into electricity is known as the cells efficiency. The ptype silicon is produced by adding atomssuch as boron or galliumthat have one less electron in their outer energy level than does silicon. This article describes the latest information achievement in the field of solar cells solar cell efficiency tables version 48 containing the latest efficiency of different types. Reconsidering the economics of photovoltaic power pdf. These constraints will be defined by the working environment in which solar cells are produced.
Since the voltage is too small for most applications, to produce a. A solar cell that is triggered by sun and rain epfl. Solar cell or photovoltaic pv cell is a device that is made up of semiconductor materials such as silicon, gallium arsenide and cadmium telluride, etc. It supplies a voltage and a current to a resistive load light, battery, motor. Solar cell multicrystalline silicon photovoltaic modules, commonly called solar modules, are the key components used to convert sunlight into electricity. The underlying motivation of this process was formulated during the enlightenment period in the 18th century as the philosophy of human progress. The working principle of a solar cell tu delft opencourseware. The boron side of the slab is 1,000 times thicker than the phosphorous. Understanding the currentvoltage characteristics of industrial crystalline. However, there are ambivalent views about solar, or photovoltaic, cells ability to supply a significant amount of energy relative to global needs. About the article working principle and development of solar cell, if you have better ideas, dont hesitate to write your thoughts in the following comment area. Silicon is an abundant material about 25% of earths crust. You may have seen the use of solar calculator from no battery calculator, sometimes calculators do not even have the close button.
The working principle of a solar cell tu delft ocw. All the aspects presented in this chapter will be discussed in greater detail in the following chapters. An example of such a material is an ntype semiconductor, in which a large electron conductivity with respect to the. Working principle of solar cell or photovoltaic cell.
Many notions presented in this chapter will be new but nonetheless the general idea of how a solar cell works should be clear. According to the carnots theorem that is a result of the second law of thermodynamics, the energy conversion efficiency of heat engines is low. The basic aspects of single junction and multi junction iiiv solar cells are available in the literature. Photovoltaics pv is the conversion of light into electricity using semiconducting materials that. This article will discuss the basic makeup of photovoltaics in. Solar panels are in turn combined to form solar arrays. Solar cell, any device that directly converts the energy of light into electrical energy through the photovoltaic effect.
Becquerel discovered the photovoltaic effect involving conversion of solar energy into electrical energy in semiconductor element. The top of the slab is very thinly diffused with an n dopant such as phosphorous. Basic photovoltaic principles and me1hods serisp2901448 solar information module 62 published february 1982 this book presents a nonmathematical explanation of the theory and design of pv solar cells and systems. Allweather solar cells are promising in solving the. Dye sensitized solar cells working principles, cha llenges and opportunities 175 fig. Schematic diagram of the band structure of an organic solar cell having only one material in the active layer and di. V principle of solar cell v current generation v iv characteristic of an illuminated pn junction v physical process of solar cell v iv characteristic of solar cell v solar cell parameter v applications v reference v device that converts optical energy into electrical energy. Solar cell is a device or a structure that converts the solar energy i. To understand and improve solar cells, it is helpful to start with their underlying principle.
A solar cell or photovoltaic cell is a device which generates electricity directly from visible light. As shown in the given diagram the solar cell is like an ordinary diode. We then apply a few finer electrodes on the top of the ptype semiconductor layer these electrodes do not obstruct light to reach the thin ptype layer. This is done using a principle known as the photovoltaic effect. A solar cell is made of two types of semiconductors, called ptype and ntype silicon. Working principle of silicon solar pv cells photovoltaic material of device converts. It consist of silicon, germanium pn junction with a glass windows on the top surface layer of ptype, the ptype material is made very thin and wide so that the. Working principles of solar and other energy conversion cells. When charged by the sun, this basic unit generates a dc photovoltage of 0. Working principles of solar and other energy conversion cells liu, wang, wang and yang 4 into electrical energy.
Understanding the currentvoltage characteristics of. Solar cell design principles solar cell design involves specifying the parameters of a solar cell structure in order to maximize efficiency, given a certain set of constraints. The working principle of a solar cell in this chapter we present a very simple model of a solar cell. Fundamental properties of solar cells, principles and varieties of. Figure 2 depicts an energy diagram of a dye solar cell. Schematic diagram of the band structure of a heterojunction organic solar cell. This is especially important for a green technology. Because boron has one less electron than is required to form the bonds with the surrounding silicon atoms, an electron vacancy or hole is created.
Principles and varieties of solar energy phys 4400 and. Solar modules are made of semiconductors that are very similar to those used to create integrated circuits for electronic equipment. Solar cells are a promising and potentially important technology and are the future of sustainable energy for the human civilization. Many different solar cell technologies are being developed, for various applications. How a photovoltaic cell works step 1 a slab or wafer of pure silicon is used to make a pv cell.
The solar cell is the basic building block of solar photovoltaics. A very thin layer of ptype semiconductor is grown on a relatively thicker ntype semiconductor. Since a solar cell only generates about 12 watts of power, it is necessary to combine them into solar power panels in order to generate more power. This type of device architecture, often referred as regular, up to now remains the most widely employed psc. So, the solar cell costs expensive according to other energy resources products.
Solar cells produce direct current electricity from sunlight which can be used to. A solar cell, or photovoltaic cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and. The overwhelming majority of solar cells are fabricated from silicon with increasing efficiency and lowering cost as the materials range from amorphous noncrystalline to polycrystalline to. Whether you are looking for general insight in this green technology or your ambition is to pursue a career in solar, introduction to solar cells is an excellent starting point. Introduction to solar cells horizon energy curriculum. The course is a tour through the fundamental disciplines including solar cell history, why we need solar energy, how solar cells produce power, and how they work. The working principle is the same as in semiconductors.
731 770 1527 654 1014 1337 401 470 1383 1128 1578 292 176 1526 1059 846 1599 681 662 1067 645 621 1231 331 1458 443 880 686 1254 134 1160