Hom ntawmphotodetector ntaus ntawvqauv
Photodetectoryog ib qho khoom siv uas hloov kho qhov muag teeb liab rau hauv hluav taws xob teeb liab, nws cov qauv thiab ntau yam, tuaj yeem muab faib ua pawg hauv qab no:
(1) Photoconductive photodetector
Thaum cov khoom siv photoconductive raug rau lub teeb, lub photogenerated cab kuj nce lawv cov conductivity thiab txo lawv cov tsis kam. Cov neeg nqa khoom zoo siab nyob rau hauv chav tsev kub txav mus rau hauv ib qho kev taw qhia raws li qhov kev txiav txim ntawm qhov hluav taws xob, yog li tsim hluav taws xob tam sim no. Nyob rau hauv qhov xwm txheej ntawm lub teeb, electrons zoo siab thiab kev hloov pauv tshwm sim. Nyob rau tib lub sij hawm, lawv drift nyob rau hauv qhov kev txiav txim ntawm ib tug hluav taws xob teb los tsim ib tug photocurrent. Qhov tshwm sim photogenerated cov nqa khoom nce cov khoom siv hluav taws xob thiab yog li txo qhov tsis kam. Photoconductive photodetectors feem ntau qhia kev nce siab thiab kev ua haujlwm zoo hauv kev ua tau zoo, tab sis lawv tsis tuaj yeem teb rau cov teeb liab ntau zaus, yog li cov lus teb ceev qeeb, uas txwv tsis pub siv cov khoom siv photoconductive hauv qee yam.
(2)PN photodetector
PN photodetector yog tsim los ntawm kev sib cuag ntawm P-type semiconductor khoom thiab N-hom semiconductor khoom. Ua ntej kev sib cuag raug tsim, ob cov ntaub ntawv yog nyob rau hauv ib lub xeev nyias. Qib Fermi nyob rau hauv P-hom semiconductor yog ze rau ntawm ntug ntawm lub valence band, thaum lub Fermi theem nyob rau hauv N-hom semiconductor yog ze rau ntawm ntug ntawm lub conduction band. Nyob rau tib lub sijhawm, Fermi qib ntawm cov khoom siv N-hom ntawm ntug ntawm cov khoom siv hluav taws xob txuas ntxiv mus kom txog rau thaum qib Fermi ntawm ob cov ntaub ntawv nyob hauv tib txoj haujlwm. Qhov kev hloov ntawm txoj hauj lwm ntawm conduction band thiab valence band kuj yog nrog kev khoov ntawm lub band. Lub PN hlws ris yog nyob rau hauv sib npaug thiab muaj ib tug zoo Fermi theem. Los ntawm nam ntawm tus nqi thauj khoom, feem ntau ntawm cov neeg nqa khoom them nqi hauv cov ntaub ntawv P-hom yog qhov, thaum feem ntau ntawm cov neeg nqa khoom them nqi hauv cov ntaub ntawv N-hom yog electrons. Thaum ob cov ntaub ntawv nyob rau hauv kev sib cuag, vim qhov sib txawv ntawm cov cab kuj concentration, cov electrons nyob rau hauv N-hom ntaub ntawv yuav diffuse mus rau P-hom, thaum lub electrons nyob rau hauv N-hom ntaub ntawv yuav diffuse nyob rau hauv lub opposite kev taw qhia rau lub qhov. Qhov chaw uas tsis tau them nyiaj tshuav los ntawm qhov diffusion ntawm electrons thiab qhov yuav tsim ib qho hluav taws xob ua hluav taws xob, thiab cov hluav taws xob tsim hluav taws xob yuav ua rau cov cab cab drift, thiab cov kev taw qhia ntawm drift tsuas yog rov qab rau cov kev taw qhia ntawm diffusion, uas txhais tau hais tias lub Kev tsim hluav taws xob tsim hluav taws xob tiv thaiv kev sib kis ntawm cov neeg nqa khoom, thiab muaj ob qho tib si diffusion thiab drift hauv PN hlws ris kom txog rau thaum ob hom kev tawm suab sib npaug, kom cov neeg nqa khoom zoo li qub yog xoom. Internal dynamic tshuav nyiaj li cas.
Thaum lub PN hlws ris raug rau lub teeb hluav taws xob, lub zog ntawm photon raug xa mus rau cov cab kuj, thiab cov neeg nqa khoom photogenerated, uas yog, photogenerated electron-qhov khub, yog generated. Nyob rau hauv qhov kev txiav txim ntawm lub teb hluav taws xob, lub electron thiab lub qhov drift mus rau thaj tsam N thiab P cheeb tsam, thiab cov directional drift ntawm lub photogenerated carrier generates photocurrent. Qhov no yog lub hauv paus ntsiab lus ntawm PN junction photodetector.
(3)PIN photodetector
Pin photodiode yog cov khoom siv P-hom thiab N-hom khoom nruab nrab ntawm I txheej, I txheej ntawm cov khoom feem ntau yog cov khoom siv los yog cov khoom siv qis. Nws cov txheej txheem ua haujlwm zoo ib yam li PN hlws ris, thaum tus PIN hlws ris raug rau lub teeb hluav taws xob, cov photon hloov lub zog rau lub tshuab hluav taws xob, tsim cov khoom siv hluav taws xob, thiab cov hluav taws xob sab hauv lossis sab nraud hluav taws xob yuav cais cov photogenerated electron-qhov. khub nyob rau hauv lub depletion txheej, thiab cov drifted chargers yuav tsim ib tug tam sim no nyob rau hauv lub sab nraud Circuit Court. Lub luag haujlwm ua los ntawm txheej kuv yog txhawm rau nthuav dav dav ntawm txheej depletion, thiab txheej kuv yuav ua tiav cov txheej txheem depletion nyob rau hauv ib qho kev tsis txaus ntseeg loj, thiab cov khoom tsim hluav taws xob-qhov khub yuav sib cais sai, yog li cov lus teb ceev PIN junction photodetector feem ntau sai dua li ntawm PN junction detector. Cov neeg nqa khoom sab nraud I txheej kuj tau sau los ntawm cov txheej txheem depletion los ntawm diffusion tsab ntawv tsa suab, ua ib qho kev nthuav dav tam sim no. Lub thickness ntawm I txheej yog feem ntau nyias nyias, thiab nws lub hom phiaj yog los txhim kho cov lus teb ceev ntawm lub ntes.
(4)APD photodetectoravalanche photodiode
Lub mechanism ntawmavalanche photodiodezoo ib yam li PN kev sib tshuam. APD photodetector siv ntau doped PN hlws ris, kev khiav hauj lwm voltage raws li APD nrhiav kom tau loj, thiab thaum ib tug loj reverse bias ntxiv, kev sib tsoo ionization thiab avalanche ntau yuav tshwm sim nyob rau hauv APD, thiab cov kev ua tau zoo ntawm lub detector yog nce photocurrent. Thaum APD nyob rau hauv txoj kev tsis ncaj ncees lawm, lub teb hluav taws xob hauv cov txheej txheem depletion yuav muaj zog heev, thiab cov khoom siv hluav taws xob uas tsim los ntawm lub teeb yuav raug sib cais sai sai thiab nrawm raws li qhov kev txiav txim ntawm hluav taws xob teb. Muaj qhov tshwm sim uas cov hluav taws xob yuav tsoo rau hauv lub lattice thaum lub sijhawm txheej txheem no, ua rau cov khoom siv hluav taws xob hauv cov lattice raug ionized. Cov txheej txheem no rov ua dua, thiab cov ionized ions hauv cov lattice kuj sib tsoo nrog cov lattice, ua rau cov neeg nqa khoom hauv APD nce ntxiv, ua rau muaj qhov tam sim no loj. Nws yog qhov tshwj xeeb ntawm lub cev lub cev hauv APD uas APD-based detectors feem ntau muaj cov yam ntxwv ntawm cov lus teb ceev ceev, cov nqi tam sim no loj thiab siab rhiab heev. Piv nrog PN junction thiab PIN junction, APD muaj cov lus teb nrawm dua, uas yog cov lus teb ceev tshaj plaws ntawm cov raj photosensitive tam sim no.
(5) Schottky hlws ris photodetector
Cov qauv yooj yim ntawm Schottky junction photodetector yog Schottky diode, uas nws cov yam ntxwv hluav taws xob zoo ib yam li cov PN kev sib tshuam tau piav qhia saum toj no, thiab nws muaj unidirectional conductivity nrog zoo conduction thiab thim rov qab. Thaum cov hlau uas muaj kev ua haujlwm siab thiab cov khoom siv hluav taws xob uas muaj kev sib cuag nrog kev ua haujlwm tsawg, Schottky barrier yog tsim, thiab qhov kev sib tshuam tshwm sim yog Schottky junction. Lub ntsiab mechanism yog me ntsis zoo li PN hlws ris, noj N-hom semiconductors ua piv txwv, thaum ob cov ntaub ntawv sib cuag, vim qhov sib txawv electron concentrations ntawm ob cov ntaub ntawv, cov electrons nyob rau hauv lub semiconductor yuav diffuse mus rau sab hlau. Cov diffused electrons sib sau ua ke tsis tu ncua ntawm ib kawg ntawm cov hlau, yog li rhuav tshem cov thawj hluav taws xob nruab nrab ntawm cov hlau, tsim ib qho hluav taws xob hauv hluav taws xob los ntawm cov khoom siv hluav taws xob mus rau cov hlau ntawm qhov chaw sib cuag, thiab cov hluav taws xob yuav ntws los ntawm qhov kev txiav txim. Cov hluav taws xob sab hauv, thiab cov neeg nqa khoom txoj kev sib kis thiab kev txav mus los yuav ua tiav ib txhij, tom qab lub sijhawm kom ncav cuag qhov sib npaug sib npaug, thiab thaum kawg tsim Schottky hlws ris. Raws li lub teeb pom kev zoo, thaj tsam teeb meem ncaj qha absorbs lub teeb thiab tsim hluav taws xob-qhov khub, thaum lub photogenerated cov cab kuj nyob rau hauv lub PN hlws ris yuav tsum dhau los ntawm lub diffusion cheeb tsam mus txog lub junction cheeb tsam. Piv nrog rau PN hlws ris, lub photodetector raws li Schottky hlws ris muaj ib tug ceev teb ceev, thiab cov lus teb ceev txawm mus txog ns.
Post lub sij hawm: Aug-13-2024