Lub hauv paus ntsiab lus ntawm lub hnub ci hluav taws xob tsim hluav taws xob yog dab tsi?

Now, more and more solar cells appear in people's field of vision. As long as there is sunlight, it can generate current, which is not too convenient. What is its principle? Today, I will briefly and slightly in-depth talk about the power generation principle of the most common crystalline silicon solar cells.

First of all, we have to introduce the raw material of crystalline silicon solar cells: silicon.These black and somewhat metallic things are polysilicon initially prepared by some chemical methods. Silicon is a semiconducting material, which means its conductivity is between that of a conductor and an insulator. Unlike metals, silicon's carriers have something called holes in addition to electrons.

Lub qhov yog dab tsi?

Muaj plaub electrons nyob rau hauv txheej txheej ntawm silicon atom. Yog tias qee qhov hluav taws xob tau txais qee lub zog los ntawm lub ntiaj teb sab nraud, lawv yuav tawg thiab dhau los ua cov hluav taws xob dawb, thiab thawj txoj hauj lwm ntawm cov hluav taws xob yuav dhau los ua qhov tsis muaj, thiab qhov chaw seem no yog lub qhov. Peb txhua tus paub tias cov khoom siv hluav taws xob tsis zoo, yog li lub qhov sib npaug rau cov neeg nqa khoom zoo.

Zoo, paub qhov no, yam tom ntej uas peb xav tham txog yog P-hom silicon thiab N-hom silicon. Qhov no yog qhov yooj yim heev, P-hom silicon txhais tau hais tias qhov yog feem ntau cov neeg nqa khoom, thiab N- hom silicon txhais tau hais tias electrons yog cov neeg nqa khoom feem ntau. Dab tsi? Koj hais tias tus naj npawb ntawm electrons thiab qhov yuav tsum yog tib yam? Hmm Yog hais tias lub purity ntawm silicon yog 100 feem pua, ntawm chav kawm tus naj npawb ntawm lawv yog tib yam, tab sis yuav ua li cas yog hais tias peb hloov ib co ntawm silicon nyob rau hauv lub caij ntawm silicon nrog ib lub caij nrog tsib electrons nyob rau hauv lub txheej txheej ntawm lub atom? Yuav ua li cas yog tias koj hloov nws nrog ib lub caij nrog tsuas yog peb lub electrons nyob rau hauv lub plhaub sab nraud?

Ob lub ntsiab feem ntau doped rau hauv silicon yog phosphorus (ntxiv rau 5 valence) thiab boron (ntxiv rau 3 valence).

Tom qab ntawd, muaj qee yam hu ua PN kev sib tshuam, uas tsis yog ib qho ntawm P-hom silicon thiab ib daim N- hom silicon. Feem ntau, ib tug nto ntawm ib daim ntawm P- hom silicon yog doped nrog phosphorus los ua ib txheej ntawm N- hom silicon, thiab vice versa, thiaj li hais tias ib tug PN hlws ris yog tsim nyob rau hauv lub cheeb tsam uas lub P-hom silicon thiab N- hom silicon interface.

Kev tsim ntawm PN kev sib tshuam yog yooj yim heev. Txij li thaum muaj ntau qhov dawb hauv P-hom silicon, thiab muaj ntau cov electrons dawb hauv N-hom silicon, vim qhov sib txawv ntawm cov concentration, cov qhov hauv P-hom silicon yuav diffuse rau hauv N-hom silicon, thaum N-hom silicon muaj ntau dawb electrons. Cov hluav taws xob hauv silicon kuj kis mus rau P-hom silicon. Ua li no, ib qho hluav taws xob yuav raug tsim nyob rau hauv qhov chaw uas P thiab N - hom silicon sib ntsib. Peb hu nws ua - nyob rau hauv hluav taws xob teb. Raws li qhov kev nthuav dav zuj zus, lub zog hluav taws xob yuav loj dua thiab loj dua, thiab cov hluav taws xob hluav taws xob yuav thawb lub qhov mus rau P- hom silicon. kev taw qhia thawb. Thaum kawg, lub zog hluav taws xob thiab qhov sib txawv ntawm qhov sib txawv ntawm qhov sib npaug, yog li tau txais kev sib tshuam PN ruaj khov.

Tam sim no rau qhov kawg. PN kev sib tshuam ua hluav taws xob li cas? Raws li ib tug semiconductor, silicon muaj lwm yam khoom tseem ceeb. Ntawd yog, thaum muaj lub teeb, cov electrons nyob rau hauv txheej txheej ntawm silicon yuav tau txais lub zog los ntawm lub teeb los ua cov electrons dawb thiab tawm hauv qhov chaw qub los ua ib qho hluav taws xob -qhov khub. Yog tias pab pawg no ntawm cov hluav taws xob- lub qhov khub tau tsim nyob rau hauv cheeb tsam uas lub chaw hluav taws xob tsim hauv PN kev sib tshuam, nyob rau hauv qhov kev txiav txim ntawm lub zog hluav taws xob, lub qhov yuav txav mus rau thaj tsam P, thiab cov hluav taws xob yuav txav mus rau thaj tsam N. Nyob rau hauv txoj kev no, muaj peev xwm sib txawv yuav raug tsim tawm thoob plaws PN kev sib tshuam. Yog tias peb txuas ob qhov kawg ntawm PN hlws ris mus rau lub electrode thiab tig nws, ib qho tam sim no yuav raug tsim.

Cov saum toj no yog lub hauv paus ntsiab lus tsim hluav taws xob ntawm lub hnub ci hlwb. Lub hauv paus ntsiab lus yog qhov yooj yim heev, tab sis nyob rau hauv cov txheej txheem ntau lawm, txhawm rau txhim kho cov roj teeb kom zoo, muaj ntau lwm cov txheej txheem uas yuav tsum tau txhim kho.