Lub hnub ci hlwb ua haujlwm li cas

Hnub ci hlwb nqus hnub ci los tsim cov haujlwm ntawm cov roj teeb zoo tib yam. Tab sis tsis zoo li cov roj teeb ib txwm muaj, qhov tso zis hluav taws xob thiab lub zog siab tshaj plaws ntawm cov roj teeb ib txwm raug kho, thaum cov zis hluav taws xob, tam sim no, thiab lub zog ntawm lub hnub ci muaj feem cuam tshuam rau cov teeb pom kev zoo thiab cov ntsiab lus ua haujlwm. Vim li no, txhawm rau siv lub hnub ci hlwb los tsim hluav taws xob, koj yuav tsum nkag siab txog kev sib raug zoo tam sim no-voltage thiab lub hauv paus ntsiab lus ntawm kev ua haujlwm ntawm lub hnub ci.

Spectral illumination ntawm lub hnub ci:

Lub zog ntawm lub hnub ci lub hnub ci yog lub hnub ci, yog li qhov kev siv thiab spectrum ntawm qhov teeb meem hnub ci txiav txim qhov tam sim no thiab qhov hluav taws xob tawm los ntawm lub hnub ci cell. Peb paub tias thaum ib yam khoom muab tso rau hauv qab lub hnub, nws tau txais lub hnub ci nyob rau hauv ob txoj kev, ib qho yog lub hnub ci ncaj qha, thiab lwm qhov yog diffuse hnub ci tom qab tawg los ntawm lwm yam khoom ntawm qhov chaw. Nyob rau hauv ib txwm muaj xwm txheej, qhov teeb meem ncaj qha suav txog li 80% ntawm lub teeb tau txais los ntawm lub hnub ci cell. Yog li ntawd, peb cov kev sib tham hauv qab no tseem yuav tsom mus rau kev raug tshav ntuj ncaj qha.

Qhov kev siv zog thiab spectrum ntawm lub hnub tuaj yeem qhia tau los ntawm spectrum irradiance, uas yog lub teeb lub zog ib chav tsev wavelength ib chav tsev (W / ㎡um). Kev siv lub hnub ci (W / ㎡) yog qhov suav ntawm tag nrho cov wavelengths ntawm spectrum illumination. Lub spectrum illumination ntawm lub hnub ci muaj feem xyuam rau qhov ntsuas qhov chaw thiab lub kaum sab xis ntawm lub hnub txheeb ze rau lub ntiaj teb saum npoo. Qhov no yog vim lub hnub ci yuav nqus thiab tawg los ntawm huab cua ua ntej mus txog lub ntiaj teb saum npoo av. Ob yam ntawm txoj hauj lwm thiab lub kaum sab xis yog feem ntau sawv cev los ntawm qhov hu ua huab cua huab cua (AM). Rau hnub ci illumination, AMO hais txog qhov xwm txheej nyob rau hauv qhov chaw sab nrauv thaum lub hnub ci ncaj qha. Nws lub teeb siv zog yog kwv yees li 1353 W / ㎡, uas yog kwv yees li qhov sib npaug ntawm lub teeb ci uas tsim los ntawm lub cev hluav taws xob nrog qhov kub ntawm 5800K. AMI hais txog qhov xwm txheej ntawm lub ntiaj teb saum npoo av, thaum lub hnub ci ncaj qha, lub teeb ci yog li 925 W / m2. AMI.5 yog hais txog qhov xwm txheej ntawm lub ntiaj teb saum npoo av, thaum lub hnub tshwm sim ntawm lub kaum sab xis ntawm 45 degrees, lub teeb ci yog li ntawm 844 W / m2. AM 1.5 feem ntau yog siv los sawv cev qhov nruab nrab illumination ntawm lub hnub ci ntawm lub ntiaj teb nto. Solar cell Circuit Court qauv:

Thaum tsis muaj lub teeb, lub hnub ci cell coj zoo li pn junction diode. Qhov tam sim no-voltage kev sib raug zoo ntawm ib tug zoo tagnrho diode yuav qhia tau hais tias

Qhov twg kuv sawv cev rau qhov tam sim no, V sawv cev rau qhov hluav taws xob, Puas yog qhov saturation tam sim no, thiab VT = KBT / q0, qhov twg KB sawv cev rau BoItzmann tas li, q0 yog lub zog hluav taws xob, thiab T yog qhov kub thiab txias. Hauv chav sov, VT = 0.026v. Nws yuav tsum raug sau tseg tias cov kev taw qhia ntawm Pn diode tam sim no txhais tau tias ntws los ntawm P-hom mus rau n-hom hauv cov cuab yeej, thiab qhov zoo thiab qhov tsis zoo ntawm qhov hluav taws xob tau txhais tias yog P-hom davhlau ya nyob twg. rho tawm cov n-type terminal muaj peev xwm. Yog li ntawd, yog hais tias qhov no txhais tau tias ua raws li, thaum lub hnub ci cell ua hauj lwm, nws voltage tus nqi yog zoo, nws tam sim no tus nqi yog tsis zoo, thiab IV nkhaus yog nyob rau hauv lub plaub quadrant. Cov neeg nyeem yuav tsum tau ceeb toom ntawm no tias qhov zoo tshaj plaws diode yog nyob ntawm ntau lub cev, thiab cov diodes tiag tiag yuav muaj qee yam tsis zoo uas cuam tshuam rau kev sib raug zoo ntawm cov cuab yeej tam sim no, xws li tiam-recombination tam sim no, ntawm no Peb yeej ' t tham ntau heev. Thaum lub hnub ci cell raug rau lub teeb, yuav muaj photocurrent hauv pn diode. Vim hais tias cov hluav taws xob ua hluav taws xob hauv qhov kev taw qhia ntawm pn kev sib tshuam yog los ntawm n-hom mus rau p-hom, cov electron-qhov khub tsim los ntawm kev nqus ntawm photons yuav khiav mus rau n-hom kawg, thaum lub qhov yuav khiav mus rau p. -type kawg. Lub photocurrent tsim los ntawm ob yuav ntws los ntawm n-hom mus rau p-hom. Feem ntau, cov kev taw qhia pem hauv ntej tam sim no ntawm lub diode txhais tau tias ntws los ntawm p-hom mus rau n-hom. Nyob rau hauv txoj kev no, piv rau ib qho zoo tagnrho diode, lub photocurrent generated los ntawm lub hnub ci cell thaum illuminated yog ib tug tsis zoo tam sim no. Qhov tam sim no-voltage kev sib raug zoo ntawm lub hnub ci cell yog qhov zoo tagnrho diode ntxiv rau qhov tsis zoo photocurrent IL, nws qhov loj yog:

Hauv lwm lo lus, thaum tsis muaj lub teeb, IL = 0, lub hnub ci cell tsuas yog ib qho zoo tib yam diode. Thaum lub hnub ci hluav taws xob luv luv, uas yog, V = 0, qhov luv-circuit tam sim no yog Isc = -IL. Uas yog hais tias, thaum lub hnub ci cell yog luv luv, lub luv luv-circuit tam sim no yog photocurrent generated los ntawm teeb meem teeb meem. Yog tias lub hnub ci hluav taws xob qhib hluav taws xob, uas yog, yog tias I = 0, nws qhov hluav taws xob qhib hluav taws xob yog:

Daim duab 2. Sib npaug ntawm lub hnub ci ntawm lub hnub ci: (a) tsis muaj, (b) nrog series thiab shunt resistors. Nws yuav tsum tau hais txog ntawm no tias qhib Circuit Court voltage thiab luv luv Circuit Court tam sim no yog ob qho tseem ceeb ntawm cov yam ntxwv ntawm lub hnub ci.

Lub hwj chim tso zis ntawm lub hnub ci cell yog cov khoom ntawm tam sim no thiab voltage:

Obviously, lub hwj chim tso zis los ntawm lub hnub ci cell tsis yog ib tug taag nqi. Nws ncav cuag tus nqi siab tshaj plaws ntawm qhov chaw ua haujlwm tam sim no-voltage, thiab qhov siab tshaj plaws tso zis hluav taws xob Pmax tuaj yeem txiav txim siab los ntawm dp / dv = 0. Peb tuaj yeem txiav txim siab tias qhov tso zis hluav taws xob ntawm qhov siab tshaj plaws tso zis hluav taws xob Pmax yog:

thiab cov zis tam sim no yog:

Qhov siab tshaj plaws tso zis zog ntawm lub hnub ci cell yog:

Kev ua tau zoo ntawm lub hnub ci cell hais txog qhov piv ntawm lub hnub ci cell hloov lub zog Pin ntawm qhov teeb meem teeb rau hauv qhov siab tshaj plaws tso zis hluav taws xob, uas yog:

Kev ntsuas kev ua haujlwm ntawm lub hnub ci dav siv lub teeb pom kev zoo ib yam li lub hnub ci nrog tus pin = 1000W / ㎡.

Kev sim, tam sim no-voltage kev sib raug zoo ntawm lub hnub ci hlwb tsis ua raws li cov lus piav qhia saum toj no. Qhov no yog vim hais tias cov cuab yeej photovoltaic nws tus kheej tau hu ua series kuj thiab shunt kuj. Rau txhua yam khoom siv semiconductor, lossis kev sib cuag ntawm semiconductor thiab hlau, yuav muaj kev tiv thaiv ntau dua lossis tsawg dua, uas yuav ua rau cov khoom siv hluav taws xob photovoltaic. Ntawm qhov tod tes, txhua txoj kev tam sim no uas tsis yog qhov zoo tshaj plaws Pn diode ntawm qhov zoo thiab qhov tsis zoo ntawm cov khoom siv photovoltaic yuav ua rau lub npe hu ua tam sim no, xws li tiam-recombination tam sim no hauv lub cuab yeej. , nto recombination tam sim no, tsis tiav ntug kev sib cais ntawm cov cuab yeej, thiab hlau tiv thaiv kev sib tshuam.

Feem ntau, peb siv shunt tsis kam los txhais cov xau tam sim no ntawm lub hnub ci, uas yog, Rsh = V / Ileak. Qhov loj dua qhov shunt tsis kam yog, qhov tsawg dua qhov xau tam sim no. Yog tias peb xav txog qhov sib koom ua ke Rs thiab shunt tsis kam Rsh, tam sim no-voltage kev sib raug zoo ntawm lub hnub ci cell tuaj yeem sau tau raws li:

Peb kuj tuaj yeem siv tsuas yog ib qho parameter, lub npe hu ua qhov tseem ceeb, los piav qhia ob qho tib si los ntawm kev ua haujlwm tsis zoo thiab shunt tsis kam. txhais tau tias:

Nws yog qhov pom tseeb tias qhov ua tau zoo tshaj plaws yog qhov siab tshaj plaws yog tias tsis muaj cov resistor thiab cov shunt kuj yog infinite (tsis muaj to tam sim no). Ib qho kev nce ntxiv hauv kev ua haujlwm los yog txo qis hauv shunt kuj yuav txo qhov ua kom tiav. Ua li no,. Kev ua haujlwm ntawm lub hnub ci tuaj yeem qhia tau los ntawm peb qhov tseem ceeb: qhib Circuit Court voltage Voc, luv Circuit Court tam sim no Isc, thiab sau qhov tseem ceeb FF.

Pom tseeb, txhawm rau txhim kho kev ua haujlwm ntawm lub hnub ci ntawm lub hnub ci, nws yog ib qho tsim nyog yuav tsum tau ua kom lub sijhawm qhib qhov hluav taws xob, luv luv Circuit Court tam sim no (uas yog, photocurrent), thiab sau qhov tseem ceeb (uas yog, txo cov kev tiv thaiv thiab cov xau tam sim no).

Qhib Circuit Court voltage thiab luv Circuit Court tam sim no: Kev txiav txim los ntawm cov qauv dhau los, qhov qhib Circuit Court voltage ntawm lub hnub ci cell yog txiav txim siab los ntawm photocurrent thiab saturated cell. Los ntawm qhov kev xav ntawm semiconductor physics, qhov qhib hluav taws xob hluav taws xob yog sib npaug ntawm Fermi lub zog sib txawv ntawm cov hluav taws xob thiab qhov nyob hauv thaj chaw them nqi. Raws li rau saturation tam sim no ntawm ib qho zoo tagnrho Pn diode, koj tuaj yeem siv:

qhia. qhov twg q0 sawv cev rau chav them nqi, ni sawv cev rau cov khoom siv hauv nruab nrab ntawm cov khoom siv hluav taws xob, ND thiab NA txhua tus sawv cev rau qhov concentration ntawm tus neeg pub dawb thiab tus txais, Dn thiab Dp txhua tus sawv cev rau diffusion coefficient ntawm electrons thiab qhov, cov lus qhia saum toj no yog xav tias n - Cov ntaub ntawv uas ob hom cheeb tsam thiab thaj tsam p-hom yog ob qho tib si dav. Feem ntau, rau lub hnub ci hlwb siv p-hom substrates, thaj tsam n-hom yog qhov ntiav heev, thiab cov lus qhia saum toj no yuav tsum tau hloov kho.

Peb tau hais ua ntej tias thaum lub hnub ci ntawm lub hnub ci teeb pom kev zoo, lub photocurrent yog generated, thiab photocurrent yog lub kaw-circuit tam sim no nyob rau hauv tam sim no-voltage kev sib raug zoo ntawm lub hnub ci cell. Ntawm no peb yuav piav luv luv txog keeb kwm ntawm photocurrent. Qhov tsim tus nqi ntawm cov cab kuj nyob rau hauv chav tsev ntim ib chav tsev ib lub sij hawm (unit m -3 s -1) yog txiav txim los ntawm lub teeb absorption coefficient, uas yog

Ntawm lawv, α sawv cev rau lub teeb nqus coefficient, uas yog qhov sib zog ntawm qhov xwm txheej photons (lossis photon flux ntom), thiab R yog hais txog qhov kev cuam tshuam coefficient, yog li nws sawv cev qhov hnyav ntawm qhov xwm txheej photons uas tsis tau xav txog. Peb lub tswv yim tseem ceeb uas tsim cov photocurrent yog: qhov diffusion tam sim no ntawm cov neeg nqaim hluav taws xob tsawg hauv cheeb tsam p-type, qhov diffusion tam sim no ntawm cov neeg nqa khoom tsawg hauv cheeb tsam n-hom, thiab qhov drift ntawm electrons thiab qhov hauv cheeb tsam chaw them nqi. tam sim no. Yog li ntawd, lub photocurrent tuaj yeem kwv yees hais tias:

Ntawm lawv, Ln thiab Lp txhua tus sawv cev qhov ntev diffusion ntawm electrons hauv thaj av p-hom thiab qhov hauv cheeb tsam n-hom, thiab yog qhov dav ntawm thaj chaw them nqi. Raws li cov txiaj ntsig no, peb tau txais cov lus qhia yooj yim rau qhov qhib hluav taws xob hluav taws xob:

qhov twg Vrcc sawv cev rau tus nqi recombination ntawm electron-qhov khub ib chav tsev ntim. Tau kawg, qhov no yog qhov tshwm sim, vim tias qhov qhib hluav taws xob hluav taws xob sib npaug sib npaug ntawm Fermi lub zog sib txawv ntawm cov hluav taws xob thiab qhov hauv thaj chaw them nqi, thiab Fermi lub zog sib txawv ntawm cov hluav taws xob thiab qhov yog txiav txim siab los ntawm cov neeg nqa khoom tsim tus nqi thiab cov nqi sib txuas. .