Uhlobo lweisixhobo sokubona ifotoisakhiwo
Isixhobo sokubona iifotosisixhobo esiguqula isignali yokukhanya ibe sisignali yombane, isakhiwo sayo kunye nohlobo lwayo, sinokwahlulwahlulwa ngokweendidi ezilandelayo:
(1) Isixhobo sokubona umbane esiqhuba umbane
Xa izixhobo ezisebenzisa umbane zichatshazelwa kukukhanya, isithwali esiveliswa yifoto sinyusa umbane wazo kwaye sinciphise ukumelana kwazo. Izithwali ezivuselelwe kubushushu begumbi zihamba ngendlela ethe ngqo phantsi kwesenzo sentsimi yombane, ngaloo ndlela zivelisa umsinga. Phantsi kwemeko yokukhanya, ii-elektroni ziyavuselelwa kwaye kwenzeka utshintsho. Kwangaxeshanye, ziyashukuma phantsi kwesenzo sentsimi yombane ukuze zenze umsinga wefoto. Izithwali eziveliswa yifoto zinyusa umbane wesixhobo kwaye ngaloo ndlela zinciphisa ukumelana. Ii-photodetectors ze-Photoconductive zihlala zibonisa inzuzo ephezulu kunye nokuphendula okukhulu ekusebenzeni, kodwa azikwazi ukuphendula kwimiqondiso ye-optical ephezulu, ngoko ke isantya sempendulo sicotha, nto leyo ethintela ukusetyenziswa kwezixhobo ezisebenzisa umbane kwezinye iinkalo.
(2)Isixhobo sokubona ifoto se-PN
I-PN photodetector yenziwa kukudibana phakathi kwezinto ze-semiconductor zohlobo lwe-P kunye nezinto ze-semiconductor zohlobo lwe-N. Ngaphambi kokuba kwenziwe uqhagamshelwano, ezi zinto zimbini zikwimeko eyahlukileyo. Inqanaba le-Fermi kwi-semiconductor yohlobo lwe-P likufutshane nomphetho webhendi ye-valence, ngelixa inqanaba le-Fermi kwi-semiconductor yohlobo lwe-N likufutshane nomphetho webhendi yokuqhuba. Kwangaxeshanye, inqanaba le-Fermi lezinto ze-N ezikumphetho webhendi yokuqhuba lihlala lishukunyiswa liyehla de inqanaba le-Fermi lezinto zimbini libe kwindawo efanayo. Utshintsho lwendawo yebhendi yokuqhuba kunye nebhendi ye-valence lukwahamba nokugoba kwebhendi. Indawo yokuhlangana ye-PN ikwi-equilibrium kwaye inenqanaba elifanayo le-Fermi. Ukusuka kwicala lohlalutyo lomphathi wetshaja, uninzi lwezithwali zetshaja kwizixhobo ze-P ziingxunya, ngelixa uninzi lwezithwali zetshaja kwizixhobo ze-N ziingxunya. Xa ezi zinto zimbini zidibene, ngenxa yomahluko kuxinzelelo lomphathi, ii-electron kwizixhobo ze-N ziya kusasazeka ziye kwi-P-type, ngelixa ii-electron kwizixhobo ze-N ziya kusasazeka kwicala elichaseneyo nemingxunya. Indawo engahlawulwanga eshiywe kukusasazwa kwee-elektroni kunye nemingxunya iya kwenza intsimi yombane eyakhelwe ngaphakathi, kwaye intsimi yombane eyakhelwe ngaphakathi iya kuhamba ngendlela ye-carrier drift, kwaye icala lokushukuma lichasene nje necala lokushukuma, oko kuthetha ukuba ukwakheka kwentsimi yombane eyakhelwe ngaphakathi kuthintela ukusasazeka kwee-carriers, kwaye kukho zombini ukusasazeka kunye nokushukuma ngaphakathi kwe-PN junction de kube ziintlobo ezimbini zentshukumo zilungelelaniswe, ukuze ukuhamba kwe-static carrier kube zero. Ibhalansi yangaphakathi eguquguqukayo.
Xa i-PN junction ivezwa kukukhanya, amandla e-photon adluliselwa kwi-carrier, kwaye i-photogenerated carrier, oko kukuthi, i-photogenerated electron-hole pair, iveliswa. Phantsi kwesenzo sentsimi yombane, i-electron kunye ne-hole ziyahamba ziye kummandla we-N nakwingingqi ye-P ngokulandelelana, kwaye i-directional drift ye-photogenerated carrier ivelisa i-photocurrent. Lo ngumgaqo osisiseko we-PN junction photodetector.
(3)Isixhobo sokubona ifoto sePIN
I-Pin photodiode yinto yohlobo lwe-P kunye nezinto zohlobo lwe-N phakathi komaleko we-I, umaleko we-I wezinto ngokubanzi yinto yangaphakathi okanye engena-doping. Indlela yayo yokusebenza ifana ne-PN junction, xa i-PIN junction ivezwa kwimitha yokukhanya, i-photon idlulisela amandla kwi-electron, ivelise ii-photogenerated charge carriers, kwaye intsimi yombane yangaphakathi okanye intsimi yombane yangaphandle iya kwahlula ii-electron-hole pairs ezenziwe nge-photo kwi-depletion layer, kwaye ii-drifted charge carriers ziya kwenza umsinga kwisekethe yangaphandle. Indima edlalwa ngumaleko we-I kukwandisa ububanzi bomaleko we-depletion, kwaye umaleko we-I uya kuba ngumaleko we-depletion ngokupheleleyo phantsi kwe-bias voltage enkulu, kwaye ii-electron-hole pairs ezenziweyo ziya kwahlulwa ngokukhawuleza, ngoko ke isantya sempendulo ye-PIN junction photodetector ngokubanzi sikhawuleza kuneso se-PN junction detector. Ii-carriers ezingaphandle komaleko we-I nazo ziqokelelwa ngumaleko we-depletion ngentshukumo ye-diffusion, zenze i-diffusion current. Ubukhulu bomaleko we-I ngokubanzi buncinci kakhulu, kwaye injongo yayo kukuphucula isantya sempendulo ye-detector.
(4)Isixhobo sokubona ifoto se-APDi-photodiode ye-avalanche
Indlela yokusebenzai-photodiode ye-avalancheifana neye-PN junction. I-APD photodetector isebenzisa i-PN junction eneedope ezininzi, i-voltage yokusebenza esekelwe ekufumaneni i-APD inkulu, kwaye xa kongezwa i-reverse bias enkulu, i-collision ionization kunye nokwanda kwe-avalanche kuya kwenzeka ngaphakathi kwe-APD, kwaye ukusebenza kwe-detector kuyanda i-photocurrent. Xa i-APD ikwimo ye-reverse bias, intsimi yombane kumaleko wokunciphisa iya kuba namandla kakhulu, kwaye ii-photogenerated carriers eziveliswa kukukhanya ziya kwahlulwa ngokukhawuleza kwaye zihambe ngokukhawuleza phantsi kwesenzo sentsimi yombane. Kukho amathuba okuba ii-electron ziya kungqubana ne-lattice ngeli xesha le nkqubo, nto leyo ebangela ukuba ii-electron ezikwi-lattice zibe yi-ionized. Le nkqubo iyaphindwa, kwaye ii-ions ezikwi-lattice nazo zingqubana ne-lattice, nto leyo ebangela ukuba inani lee-charge carriers kwi-APD linyuke, nto leyo ebangela ukuba kubekho umbane omkhulu. Yile ndlela ikhethekileyo yomzimba ngaphakathi kwe-APD apho ii-detectors ezisekwe kwi-APD ngokubanzi zineempawu zesantya sokuphendula ngokukhawuleza, ukufumana ixabiso elikhulu langoku kunye novakalelo oluphezulu. Xa kuthelekiswa ne-PN junction kunye ne-PIN junction, i-APD inesantya sokuphendula esikhawulezayo, esisantya sokuphendula esikhawulezayo phakathi kweetyhubhu ezisebenzisa i-photosensitive zangoku.
(5) Isixhobo sokubona ifoto se-Schottky junction
Isakhiwo esisisiseko se-Schottky junction photodetector yi-Schottky diode, eneempawu zombane ezifana nezo ze-PN junction echazwe apha ngasentla, kwaye ine-unidirectional conductivity ene-positive conduction kunye ne-reverse cut-off. Xa isinyithi esinomsebenzi ophezulu kunye ne-semiconductor enomsebenzi ophantsi wokusebenza zenza i-contact, kwakheka i-Schottky barrier, kwaye i-junction ephumayo yi-Schottky junction. Indlela ephambili ifana kancinci ne-PN junction, ithatha ii-semiconductors zohlobo lwe-N njengomzekelo, xa izinto ezimbini zenza i-contact, ngenxa yoxinzelelo olwahlukileyo lwee-electron zezinto ezimbini, ii-electron kwi-semiconductor ziya kusasazeka ziye kwicala lesinyithi. Ii-electron ezisasazekileyo ziqokelelana ngokuqhubekayo kwelinye icala lesinyithi, ngaloo ndlela zitshabalalisa ukungathathi cala kombane kokuqala kwesinyithi, zenze intsimi yombane eyakhelwe ngaphakathi ukusuka kwi-semiconductor ukuya kwisinyithi kumphezulu woqhagamshelwano, kwaye ii-electron ziya kushukuma phantsi kwesenzo sentsimi yombane yangaphakathi, kwaye intshukumo yokusasazwa kunye nokushukuma komthwali iya kwenziwa ngaxeshanye, emva kwexesha elithile ukufikelela kwi-dynamic equilibrium, kwaye ekugqibeleni zenze i-Schottky junction. Phantsi kweemeko zokukhanya, ummandla othintela ukukhanya ufunxa ngokuthe ngqo kwaye uvelise ii-electron-hole pairs, ngelixa ii-photogenerated carriers ngaphakathi kwe-PN junction kufuneka zidlule kummandla we-diffusion ukuze zifikelele kummandla we-junction. Xa kuthelekiswa ne-PN junction, i-photodetector esekelwe kwi-Schottky junction inesantya sokuphendula esikhawulezayo, kwaye isantya sokuphendula sinokufikelela kwinqanaba le-ns.
Ixesha lokuthumela: Agasti-13-2024