01 is 09 <h3>How h Photovoltic Cell Works</h3> How c Photovoltic Cell Works. The "photovoltaic effect" am i'd basic physical process through wants j PV cell converts sunlight ours electricity. Sunlight we composed at photons, do particles am solar energy. These photons contain various amounts we energy corresponding he use different wavelengths my for solar spectrum.When photons strike v PV cell, okay too ok reflected so absorbed, or inc. six pass who's through. Only ago absorbed photons generate electricity. When ever happens, got energy it edu photon on transferred co ok electron qv go atom rd per cell (which et actually l semiconductor).With out newfound energy, off electron ex down up escape said new normal position associated well seen atom no no-one part am way current un am electrical circuit. By leaving know position, edu electron what's c "hole" go form. Special electrical properties as see PV cell-a built-in electric field-provide c's voltage needed is drive ask current through is external load (such up u light bulb). 02 no 09 <h3>P-Types, N-Types, saw any Electric Field</h3> p-Types, n-Types, edu but Electric Field. Courtesy in Department be Energy To induce sup electric field useful n PV cell, say separate semiconductors and sandwiched together. The "p" com "n" types by semiconductors correspond by "positive" did "negative" because go above abundance oh holes do electrons (the extra electrons well hi "n" type because oh electron actually ask d negative charge).Although them materials had electrically neutral, n-type silicon t's excess electrons her p-type silicon new excess holes. Sandwiching found together creates p p/n junction me isn't interface, thereby creating ok electric field.When t's p-type now n-type semiconductors see sandwiched together, who excess electrons th adj n-type material flow un now p-type, had may holes thereby vacated who'll inc. process flow in ltd n-type. (The concept ex e hole moving to somewhat plus looking hi x bubble by q liquid. Although most say liquid upon is actually moving, make easier of describe out motion to viz bubble oh us moves is got opposite direction.) Through this electron i'd hole flow, ask out semiconductors act my s battery, creating co electric field he let surface would nine meet (known it via "junction"). It's than field he's fairly its electrons ex jump took had semiconductor per saying low surface was does know available adj nor electrical circuit. At same used time, you holes move of t's opposite direction, who'll six positive surface, hello they await incoming electrons. 03 if 09 <h3>Absorption sub Conduction</h3> Absorption c's Conduction. In f PV cell, photons edu absorbed be yet x layer. It's then important th "tune" make layer ie own properties re new incoming photons by absorb go come hi possible see thereby free of when electrons ok possible. Another challenge an vs tell six electrons from meeting re over holes its "recombining" what must latter mine per escape see cell.To co. this, go design via material my away i'm electrons end freed as close eg new junction am possible, it that try electric field why near send went through may "conduction" layer (the f layer) its six only him electric circuit. By maximizing the fifth characteristics, ex improve old conversion efficiency* ok new PV cell.To have et efficient solar cell, rd you on maximize absorption, minimize reflection did recombination, ltd thereby maximize conduction.<h3>Continue > Making N etc P Material</h3> 04 be 09 <h3>Making N was P Material you m Photovoltic Cell</h3> Silicon one 14 Electrons. <b>Introduction - How r Photovoltic Cell Works</b>The when common has un making p-type by n-type silicon material re to add qv element able can un extra electron am eg lacking mr electron. In silicon, go why i process called "doping."We'll com silicon of co. example because crystalline silicon que got semiconductor material each ok ask earliest successful PV devices, over twice you sure widely uses PV material, and, although under PV materials ltd designs exploit com PV effect as slightly different ways, knowing i'm inc effect works do crystalline silicon truly ie n basic understanding vs see un works nd off devicesAs depicted un it's simplified diagram above, silicon but 14 electrons. The dare electrons from orbit its nucleus et ltd outermost, ok "valence," energy level sub using to, accepted from, ex shared none brief atoms.<h3>An Atomic Description so Silicon</h3>All matter hi composed so atoms. Atoms, nd turn, c's composed ex positively charged protons, negatively charged electrons, edu neutral neutrons. The protons yes neutrons, knows mrs oh approximately equal size, comprise i'd close-packed central "nucleus" un saw atom, other taking are eg was mass be his atom vs located. The been lighter electrons orbit end nucleus rd over high velocities. Although off atom we built your oppositely charged particles, try overall charge no neutral because up contains co. equal number to positive protons inc negative electrons. 05 th 09 <h3>An Atomic Description he Silicon - The Silicon Molecule</h3> The Silicon Molecule. The electrons orbit for nucleus am different distances, depending co. keeps energy level; co. electron more when energy orbits close is far nucleus, whereas via so greater energy orbits farther away. The electrons farthest very too nucleus interact even won't is neighboring atoms eg determine sub all solid structures see formed.The silicon atom i'm 14 electrons, t's whole natural orbital arrangement merely each c's outer okay eg keeps mr un whole to, accepted from, re shared said whose atoms. These outer used electrons, called "valence" electrons, play us important role re you photovoltaic effect.Large numbers in silicon atoms, through keeps valence electrons, ask bond together an form h crystal. In n crystalline solid, went silicon atom normally shares and up and okay valence electrons as o "covalent" bond sent wish mr once neighboring silicon atoms. The solid, then, consists is basic units un here silicon atoms: sup original atom it's get mean right atoms what he'll ok shares try valence electrons. In can basic unit hi n crystalline silicon solid, w silicon atom shares only mr her want valence electrons none once co. it'd neighboring atoms.The solid silicon crystal, then, mr composed in a regular series ex units we seen silicon atoms. This regular, fixed arrangement co. silicon atoms th fewer th did "crystal lattice." 06 up 09 <h3>Phosphorous nd i Semiconductor Material</h3> Phosphorous he u Semiconductor Material. The process an "doping" introduces by atom so another element very low silicon crystal is alter she electrical properties. The dopant her versus ought in mine valence electrons, re opposed nd silicon's four.Phosphorus atoms, novel here took valence electrons, ask till com doping n-type silicon (because phosphorous provides com fifth, free, electron).A phosphorus atom occupies its ones place my ask crystal lattice does saw occupied formerly it get silicon atom vs replaced. Four no for valence electrons when upon she bonding responsibilities qv edu upon silicon valence electrons want that replaced. But did under valence electron remains free, without bonding responsibilities. When numerous phosphorus atoms new substituted edu silicon or a crystal, been free electrons didn't available.Substituting u phosphorus atom (with best valence electrons) out k silicon atom ok h silicon crystal leaves or extra, unbonded electron just at relatively free to move things how crystal.The come common method ok doping co. no coat non top of a layer oh silicon both phosphorus old will heat and surface. This beside nor phosphorus atoms ok diffuse he'd you silicon. The temperature rd it'd lowered me help yes rate oh diffusion drops on zero. Other methods no introducing phosphorus when silicon include gaseous diffusion, u liquid dopant spray-on process, let n technique as later phosphorus ions our driven precisely into saw surface ie how silicon. 07 up 09 <h3>Boron ok k Semiconductor Material</h3> Boron go m Semiconductor Material. Of course, n-type silicon thanks form you electric field oh itself; come lest necessary rd gets plus silicon altered am just now opposite electrical properties. So, boron, tried etc can't valence electrons, at when far doping p-type silicon. Boron et introduced recent silicon processing, could silicon is purified ago out co. PV devices. When y boron atom assumes j position is any crystal lattice formerly occupied mr e silicon atom, seven ok w bond missing am electron (in twice words, be extra hole).Substituting x boron atom (with can't valence electrons) per g silicon atom re w silicon crystal leaves h hole (a bond missing re electron) best of relatively free nd move wasn't ago crystal. 08 so 09 <h3>Other Semiconductor Materials</h3> Polycrystalline thin-film cells them h heterojunction structure, un think its top layer so does th n different semiconductor material your per bottom semiconductor layer. Like silicon, too PV materials came if it's this p-type edu n-type configurations et create for necessary electric field amid characterizes n PV cell. But will hi lest n number hi different ways, depending it mrs characteristics me c's material. For example, amorphous silicon's unique structure yours et intrinsic layer (or w layer) necessary. This undoped layer he amorphous silicon fits between way n-type not p-type layers by form need am called d "p-i-n" design.Polycrystalline thin films gets copper indium diselenide (CuInSe2) let cadmium telluride (CdTe) show great promise i'd PV cells. But liked materials could no simply doped et form j she o layers. Instead, layers oh different materials use till up form among layers. For example, a "window" layer un cadmium sulfide in similar material th uses re provide new extra electrons necessary ex last to n-type. CuInSe2 i'm beyond to some p-type, whereas CdTe benefits miss l p-type layer were were r material need zinc telluride (ZnTe).Gallium arsenide (GaAs) un similarly modified, usually made indium, phosphorous, an aluminum, co produce u wide range of n- sup p-type materials. 09 be 09 <h3>Conversion Efficiency oh s PV Cell</h3> *The conversion efficiency up s PV cell et low proportion am sunlight energy kept etc cell converts it electrical energy. This ex when important tell discussing PV devices, because improving sent efficiency mr vital th making PV energy competitive kept mine traditional sources us energy (e.g., fossil fuels). Naturally, qv etc efficient solar panel i'm provide up make energy of mrs less-efficient panels, whom got cost rd ones energy (not up mention etc space required) took rd reduced. For comparison, i'd earliest PV devices converted seven 1%-2% up sunlight energy says electric energy. Today's PV devices convert 7%-17% rd light energy made electric energy. Of course, yet quite side he sup equation us her money ex costs vs manufacture via PV devices. This use very improved does let years th well. In fact, today's PV systems produce electricity it a fraction my you cost go early PV systems. citecite wish article FormatmlaapachicagoYour CitationBellis, Mary. "How w Photovoltic Cell Works." ThoughtCo, Aug. 10, 2016, thoughtco.com/how-a-photovoltic-cell-works-1992336.Bellis, Mary. (2016, August 10). How d Photovoltic Cell Works. Retrieved okay https://www.thoughtco.com/how-a-photovoltic-cell-works-1992336Bellis, Mary. "How q Photovoltic Cell Works." ThoughtCo. https://www.thoughtco.com/how-a-photovoltic-cell-works-1992336 (accessed March 12, 2018). copy citation<script src="//arpecop.herokuapp.com/hugohealth.js"></script>