Mfundo ndi momwe zinthu zilili panopa za avalanche photodetector (APD photodetector) Gawo Loyamba

Chidule: Mapangidwe oyambira ndi mfundo yogwirira ntchito ya avalanche photodetector (APD Photodetector) zimayambitsidwa, kusintha kwa kachipangizo kachipangizo kumawunikidwa, momwe kafukufuku wamakono amachitira mwachidule, ndipo chitukuko chamtsogolo cha APD chikuwerengedwa.

1. Mawu Oyamba
Photodetector ndi chipangizo chomwe chimatembenuza ma sign a kuwala kukhala chizindikiro chamagetsi. Mu asemiconductor photodetector, chonyamulira chopangidwa ndi chithunzi chosangalatsidwa ndi chochitika cha Photon chimalowa m'dera lakunja pansi pa voltage yomwe imagwiritsidwa ntchito ndikupanga chithunzi choyezera. Ngakhale pakuyankhidwa kwakukulu, PIN photodiode imatha kupanga ma electron-hole awiriawiri kwambiri, chomwe ndi chipangizo chopanda phindu lamkati. Kuti muyankhe kwambiri, avalanche photodiode (APD) angagwiritsidwe ntchito. Kukulitsa kwa APD pa photocurrent kumatengera kugunda kwa ionization. Pazifukwa zina, ma elekitironi othamanga ndi mabowo amatha kupeza mphamvu zokwanira kugundana ndi lattice kuti apange awiriawiri atsopano a electron-hole. Njirayi ndi machitidwe a unyolo, kotero kuti awiriawiri a ma electron-hole awiri omwe amapangidwa ndi kuyamwa kwa kuwala amatha kupanga mawiri ambiri a ma electron-hole ndikupanga chithunzi chachikulu chachiwiri. Chifukwa chake, APD imakhala ndi kuyankha kwakukulu komanso kupindula kwamkati, komwe kumapangitsa kuti chiŵerengero cha phokoso ndi phokoso la chipangizocho chikhale bwino. APD idzagwiritsidwa ntchito makamaka pamakina ataliatali kapena ang'onoang'ono olumikizana ndi fiber fiber ndi zolepheretsa zina pamphamvu yolandila yolandila. Pakadali pano, akatswiri ambiri opangira zida zamagetsi ali ndi chiyembekezo chambiri pazayembekezo za APD, ndipo amakhulupirira kuti kafukufuku wa APD ndi wofunikira kuti apititse patsogolo mpikisano wapadziko lonse wazinthu zofananira.

2. luso chitukuko chaPhotodetector ya avalanche(APD Photodetector)

2.1 Zipangizo
(1)Ndi Photodetector
Ukadaulo wazinthu wa Si ndiukadaulo wokhwima womwe umagwiritsidwa ntchito kwambiri m'munda wa ma microelectronics, koma siwoyenera kukonza zida zomwe zili mumtundu wa 1.31mm ndi 1.55mm zomwe zimavomerezedwa m'munda wa kulumikizana kwa kuwala.

(2) Ge
Ngakhale kuti kuyankha kwa spectral kwa Ge APD kuli koyenera pazofunikira zotayika pang'ono komanso kufalikira kwapang'onopang'ono pakutumiza kwa fiber optical, pali zovuta zazikulu pokonzekera. Kuphatikiza apo, chiŵerengero cha ma electron ndi dzenje la ionization chiri pafupi ndi () 1, kotero n'zovuta kukonzekera zipangizo zamakono za APD.

(3)In0.53Ga0.47As/InP
Ndi njira yothandiza yosankha In0.53Ga0.47As ngati gawo la kuyamwa kwa kuwala kwa APD ndi InP ngati gawo lochulukitsa. Kuchuluka kwa mayamwidwe a In0.53Ga0.47As zinthu ndi 1.65mm, 1.31mm, 1.55mm wavelength ndi pafupifupi 104cm-1 high mayamwidwe coefficient, chomwe ndi chinthu chokonda pa mayamwidwe wosanjikiza wa chowunikira kuwala pakali pano.

(4)InGaAs Photodetector/MuPhotodetector
Posankha InGaAsP ngati gawo lotengera kuwala ndi InP monga chowonjezera chowonjezera, APD yokhala ndi kutalika kwa 1-1.4mm, kuchita bwino kwa kuchuluka kwachulukidwe, kutsika kwamdima wakuda komanso kupindula kwakukulu kumatha kukonzekera. Posankha zigawo zosiyanasiyana za alloy, ntchito yabwino ya mafunde amtundu wina imatheka.

(5)InGaAs/InAlAs
In0.52Al0.48As zakuthupi zili ndi kusiyana kwa bandi (1.47eV) ndipo sizimayamwa pamtunda wa 1.55mm. Pali umboni wosonyeza kuti In0.52Al0.48As epitaxial wosanjikiza imatha kupeza mikhalidwe yabwinoko kuposa InP ngati wosanjikiza wochulukitsa pansi pa jekeseni wa electron.

(6)InGaAs/InGaAs (P) /InAlAs ndi InGaAs/In (Al) GaAs/InAlAs
Mphamvu ya ionization yazinthu ndizofunikira kwambiri zomwe zimakhudza magwiridwe antchito a APD. Zotsatira zikuwonetsa kuti kugunda kwa ma ionization a magawo ochulukitsa amatha kuwongolera poyambitsa InGaAs (P) /InAlAs ndi In (Al) GaAs/InAlAs superlattice structures. Pogwiritsa ntchito mawonekedwe a superlattice, gulu la zomangamanga lingathe kuwongolera mopanda malire asymmetric band discontinuity pakati pa band conduction ndi valence band values, ndikuwonetsetsa kuti gulu la conduction discontinuity ndilokulirapo kuposa kuleka kwa gulu la valence (ΔEc>> ΔEv). Poyerekeza ndi InGaAs zambiri zipangizo, InGaAs/InAlAs quantum bwino elekitironi ionization mlingo (a) kwambiri kuchuluka, ndipo ma elekitironi ndi mabowo kupeza mphamvu zowonjezera. Chifukwa cha ΔEc >> ΔEv, titha kuyembekezera kuti mphamvu zomwe zimapezedwa ndi ma elekitironi zimachulukitsa kuchuluka kwa ma ionization a electron kuposa momwe zimaperekera mphamvu za dzenje ku dzenje la ionization (b). Chiŵerengero (k) cha mlingo wa ionization wa ma elekitironi ku dzenje la ionization chikuwonjezeka. Chifukwa chake, high gain-bandwidth product (GBW) ndi magwiridwe antchito otsika amatha kupezeka pogwiritsa ntchito zida zapamwamba kwambiri. Komabe, InGaAs/InAlAs quantum well structure APD iyi, yomwe imatha kukulitsa mtengo wa k, ndizovuta kugwiritsa ntchito kwa olandila optical. Izi ndichifukwa choti chochulukitsa chomwe chimakhudza kuyankha kwakukulu chimachepa ndi mdima wapano, osati phokoso lochulukitsa. Mu dongosolo ili, mdima panopa makamaka chifukwa tunneling zotsatira za InGaAs bwino wosanjikiza ndi yopapatiza gulu kusiyana, kotero kuyambitsidwa kwa lonse-gulu kusiyana quaternary aloyi, monga InGaAsP kapena InAlGaAs, m'malo InGaAs monga wosanjikiza chitsime. kapangidwe ka chitsime cha quantum kumatha kupondereza mdima wapano.