Hom qauv ntawm cov khoom siv photodetector

Hom ntawmlub cuab yeej ntes duabqauv
Lub tshuab ntes duabyog ib lub cuab yeej uas hloov cov teeb liab kho qhov muag mus rau hauv cov teeb liab hluav taws xob, nws cov qauv thiab ntau yam, feem ntau yog muab faib ua pawg hauv qab no:
(1) Lub tshuab ntes duab photoconductive
Thaum cov khoom siv photoconductive raug rau lub teeb, cov khoom siv photogenerated ua rau lawv cov conductivity nce thiab txo lawv qhov tsis kam. Cov khoom siv uas tau excited ntawm chav tsev kub txav mus rau hauv ib txoj kev taw qhia nyob rau hauv qhov kev ua ntawm lub teb hluav taws xob, yog li tsim cov tam sim no. Nyob rau hauv lub xeev ntawm lub teeb, electrons raug excited thiab kev hloov pauv tshwm sim. Tib lub sijhawm, lawv drift nyob rau hauv qhov kev ua ntawm lub teb hluav taws xob los tsim cov photocurrent. Cov khoom siv photogenerated ua rau cov khoom siv conductivity nce thiab yog li txo qhov tsis kam. Cov photoconductive photodetectors feem ntau qhia tau tias muaj kev nce siab thiab teb zoo hauv kev ua tau zoo, tab sis lawv tsis tuaj yeem teb rau cov teeb liab optical siab, yog li qhov ceev teb qeeb, uas txwv tsis pub siv cov khoom siv photoconductive hauv qee qhov.

(2)PN photodetector
PN photodetector yog tsim los ntawm kev sib cuag ntawm cov khoom siv semiconductor P-hom thiab cov khoom siv semiconductor N-hom. Ua ntej kev sib cuag raug tsim, ob yam khoom siv nyob rau hauv ib lub xeev sib cais. Qib Fermi hauv P-hom semiconductor nyob ze rau ntug ntawm valence band, thaum qib Fermi hauv N-hom semiconductor nyob ze rau ntug ntawm conduction band. Tib lub sijhawm, qib Fermi ntawm N-hom khoom siv ntawm ntug ntawm conduction band txuas ntxiv mus txog thaum qib Fermi ntawm ob yam khoom siv nyob rau tib qho chaw. Kev hloov pauv ntawm txoj haujlwm ntawm conduction band thiab valence band kuj nrog los ntawm kev khoov ntawm band. Lub PN junction yog nyob rau hauv qhov sib npaug thiab muaj qib Fermi sib xws. Los ntawm qhov ntawm kev tshuaj xyuas tus neeg nqa khoom them, feem ntau ntawm cov neeg nqa khoom them hauv P-hom khoom siv yog qhov, thaum feem ntau ntawm cov neeg nqa khoom them hauv N-hom khoom siv yog electrons. Thaum ob yam khoom siv sib cuag, vim qhov sib txawv ntawm kev sib sau ua ke, cov electrons hauv N-hom khoom siv yuav diffuse rau P-hom, thaum cov electrons hauv N-hom khoom siv yuav diffuse rau hauv qhov kev taw qhia rov qab rau qhov. Thaj chaw tsis tau them rov qab los ntawm kev sib kis ntawm cov electrons thiab qhov yuav tsim ib lub teb hluav taws xob uas ua rau hauv, thiab lub teb hluav taws xob uas ua rau hauv yuav hloov pauv tus neeg nqa khoom, thiab qhov kev taw qhia ntawm kev txav mus los yog qhov sib txawv ntawm qhov kev taw qhia ntawm kev sib kis, uas txhais tau tias kev tsim ntawm lub teb hluav taws xob uas ua rau hauv tiv thaiv kev sib kis ntawm cov neeg nqa khoom, thiab muaj ob qho tib si kev sib kis thiab kev txav mus los hauv PN sib tshuam kom txog thaum ob hom kev txav mus los sib npaug, yog li ntawd qhov ntws ntawm tus neeg nqa khoom zoo li qub yog xoom. Kev sib npaug sab hauv.
Thaum lub PN junction raug rau lub teeb ci, lub zog ntawm photon raug xa mus rau tus neeg nqa khoom, thiab tus neeg nqa khoom photogenerated, uas yog, tus khub electron-hole photogenerated, raug tsim. Nyob rau hauv qhov kev ua ntawm lub zog hluav taws xob, lub electron thiab qhov drift mus rau thaj tsam N thiab thaj tsam P, thiab qhov kev taw qhia ntawm tus neeg nqa khoom photogenerated tsim photocurrent. Qhov no yog lub hauv paus ntsiab lus ntawm PN junction photodetector.

(3)Tus ntsuas duab PIN
Pin photodiode yog cov khoom siv P-hom thiab cov khoom siv N-hom ntawm I txheej, I txheej ntawm cov khoom siv feem ntau yog cov khoom siv intrinsic lossis low-doping. Nws txoj haujlwm ua haujlwm zoo ib yam li PN junction, thaum PIN junction raug rau lub teeb ci, photon hloov lub zog mus rau electron, tsim cov photogenerated charge carriers, thiab lub tshav fais fab sab hauv lossis lub tshav fais fab sab nraud yuav cais cov photogenerated electron-hole khub hauv depletion txheej, thiab cov drifted charge carriers yuav tsim ib qho tam sim no hauv lub voj voog sab nraud. Lub luag haujlwm ua si los ntawm txheej I yog kom nthuav dav qhov dav ntawm depletion txheej, thiab txheej I yuav ua tiav tag nrho cov depletion txheej nyob rau hauv lub zog loj bias, thiab cov electron-hole khub tsim yuav raug sib cais sai, yog li qhov teb ceev ntawm PIN junction photodetector feem ntau sai dua li ntawm PN junction detector. Cov carriers sab nraum I txheej kuj tau sau los ntawm depletion txheej los ntawm diffusion txav, tsim ib qho diffusion tam sim no. Lub thickness ntawm I txheej feem ntau yog nyias heev, thiab nws lub hom phiaj yog los txhim kho qhov teb ceev ntawm lub detector.

(4)APD photodetectorphotodiode av qeeg
Lub mechanism ntawmphotodiode av qeegzoo ib yam li PN junction. APD photodetector siv cov PN junction uas muaj doped ntau heev, qhov voltage ua haujlwm raws li APD detection loj heev, thiab thaum ntxiv qhov reverse bias loj, collision ionization thiab avalanche multiplication yuav tshwm sim hauv APD, thiab qhov kev ua haujlwm ntawm lub detector yog nce photocurrent. Thaum APD nyob rau hauv hom reverse bias, lub teb hluav taws xob hauv txheej depletion yuav muaj zog heev, thiab cov photogenerated carriers uas tsim los ntawm lub teeb yuav raug sib cais sai sai thiab sai sai drift nyob rau hauv qhov kev ua ntawm lub teb hluav taws xob. Muaj qhov tshwm sim uas cov electrons yuav tsoo rau hauv lub lattice thaum lub sijhawm no, ua rau cov electrons hauv lub lattice raug ionized. Cov txheej txheem no rov ua dua, thiab cov ionized ions hauv lub lattice kuj sib tsoo nrog lub lattice, ua rau tus lej ntawm cov charge carriers hauv APD nce ntxiv, ua rau muaj tam sim no loj. Nws yog lub cev tshwj xeeb no hauv APD uas APD-based detectors feem ntau muaj cov yam ntxwv ntawm kev teb ceev ceev, qhov nce tam sim no loj thiab kev rhiab heev. Piv nrog rau PN junction thiab PIN junction, APD muaj qhov ceev teb sai dua, uas yog qhov ceev teb sai tshaj plaws ntawm cov raj photosensitive tam sim no.

(5) Lub tshuab ntsuas duab Schottky sib tshuam
Lub qauv yooj yim ntawm Schottky junction photodetector yog Schottky diode, uas nws cov yam ntxwv hluav taws xob zoo ib yam li cov ntawm PN junction piav qhia saum toj no, thiab nws muaj kev coj ua unidirectional nrog kev coj ua zoo thiab kev txiav rov qab. Thaum cov hlau uas muaj kev ua haujlwm siab thiab semiconductor nrog kev ua haujlwm qis tsim kev sib cuag, Schottky barrier tsim, thiab qhov sib txuas ua ke yog Schottky junction. Lub tshuab tseem ceeb zoo ib yam li PN junction, coj N-hom semiconductors ua piv txwv, thaum ob yam khoom tsim kev sib cuag, vim muaj qhov sib txawv ntawm cov electron concentration ntawm ob yam khoom, cov electrons hauv semiconductor yuav diffuse mus rau sab hlau. Cov electrons diffused sib sau ua ke tas li ntawm ib kawg ntawm cov hlau, yog li rhuav tshem qhov hluav taws xob neutrality qub ntawm cov hlau, tsim ib lub teb hluav taws xob ua los ntawm semiconductor mus rau hlau ntawm qhov chaw sib cuag, thiab cov electrons yuav drift nyob rau hauv qhov kev ua ntawm lub teb hluav taws xob sab hauv, thiab tus neeg nqa khoom diffusion thiab drift txav yuav raug nqa tawm tib lub sijhawm, tom qab ib lub sijhawm kom mus txog dynamic equilibrium, thiab thaum kawg tsim Schottky junction. Nyob rau hauv lub teeb pom kev zoo, thaj chaw thaiv ncaj qha nqus lub teeb thiab tsim cov khub electron-hole, thaum cov photogenerated carriers hauv PN junction yuav tsum dhau los ntawm thaj chaw diffusion kom mus txog thaj chaw junction. Piv nrog PN junction, lub photodetector raws li Schottky junction muaj qhov ceev teb sai dua, thiab qhov ceev teb tuaj yeem ncav cuag ns theem.