Mtundu wa mawonekedwe a chipangizo cha photodetector

Mtundu waPhotodetector chipangizokapangidwe
Photodetectorndi chipangizo chomwe chimasintha chizindikiro cha kuwala kukhala chizindikiro chamagetsi, kapangidwe kake ndi zosiyanasiyana, zikhoza kugawidwa m'magulu otsatirawa:
(1) Photoconductive Photodetector
Zida za photoconductive zikawululidwa, chonyamulira cha photogenerated chimawonjezera kuwongolera kwawo ndikuchepetsa kukana kwawo. Zonyamulira zomwe zimakondwera ndi kutentha kwa chipinda zimayenda molunjika pansi pa ntchito ya magetsi, motero zimapanga panopa. Pansi pa kuwala, ma electron amasangalala ndipo kusintha kumachitika. Panthawi imodzimodziyo, amayendayenda pansi pa ntchito ya magetsi kuti apange photocurrent. The chifukwa photogenerated zonyamulira kumawonjezera madutsidwe wa chipangizo motero kuchepetsa kukana. Photoconductive photodetectors nthawi zambiri amawonetsa kupindula kwakukulu ndi kuyankha kwakukulu pakugwira ntchito, koma sangathe kuyankha zizindikiro zowoneka bwino kwambiri, kotero kuti liwiro la kuyankha limakhala lapang'onopang'ono, zomwe zimalepheretsa kugwiritsa ntchito zipangizo za photoconductive pazinthu zina.

(2)PN Photodetector
PN photodetector imapangidwa ndi kukhudzana pakati pa P-mtundu semiconductor chuma ndi N-mtundu semiconductor zakuthupi. Kulumikizana kusanapangidwe, zida ziwirizi zimakhala zosiyana. Mulingo wa Fermi mu semiconductor yamtundu wa P uli pafupi ndi m'mphepete mwa gulu la valence, pomwe mulingo wa Fermi mu semiconductor yamtundu wa N uli pafupi ndi m'mphepete mwa gulu lowongolera. Nthawi yomweyo, mulingo wa Fermi wa zinthu zamtundu wa N m'mphepete mwa bandi yowongolera umasunthidwa mosalekeza mpaka mulingo wa Fermi wa zida ziwirizo uli pamalo amodzi. Kusintha kwa malo a conduction band ndi valence band kumaphatikizidwanso ndi kupindika kwa gululo. Mzere wa PN uli wofanana ndipo uli ndi mulingo wa Fermi wofanana. Kuchokera kumbali ya kusanthula kwa chonyamulira, zonyamulira zambiri muzinthu zamtundu wa P ndi mabowo, pomwe zonyamulira zambiri muzinthu zamtundu wa N ndi ma elekitironi. Pamene zipangizo ziwirizi zikukhudzana, chifukwa cha kusiyana kwa ndende yonyamulira, ma electron mu zipangizo zamtundu wa N adzafalikira ku mtundu wa P, pamene ma electron mu zipangizo zamtundu wa N adzafalikira mosiyana ndi mabowo. Malo osalipidwa omwe amasiyidwa ndi kufalikira kwa ma elekitironi ndi mabowo adzapanga malo opangira magetsi, ndipo gawo lamagetsi lomwe limamangidwamo lidzakhala loyendetsa chonyamulira, ndipo komwe kumayendera kumakhala kosiyana ndi komwe kumafalikira, zomwe zikutanthauza kuti kupangidwa kwa malo opangira magetsi kumalepheretsa kufalikira kwa zonyamulira, ndipo pali kufalikira ndi kugwedezeka mkati mwa mphambano ya PN mpaka mitundu iwiri ya zoyendayo ikhale yabwino, kotero kuti kuyenda kwa static carrier ndi ziro. Internal zosinthika bwino.
Pamene mgwirizano wa PN umawonekera ku kuwala kwa kuwala, mphamvu ya photon imasamutsidwa kwa chonyamulira, ndipo chonyamulira cha photogenerated, ndiko kuti, chithunzi chojambulidwa cha electron-hole pair, chimapangidwa. Pansi pa ntchito ya magetsi, ma elekitironi ndi dzenje zimasunthika kupita kudera la N ndi dera la P motsatana, ndipo kutengeka kolowera kwa chonyamulira chojambulidwa kumapanga chithunzithunzi. Ili ndiye mfundo yofunikira ya PN junction photodetector.

(3)Pin photodetector
Pin photodiode ndi zinthu zamtundu wa P ndi zinthu zamtundu wa N pakati pa I wosanjikiza, wosanjikiza wa I wa zinthuzo nthawi zambiri ndi wamkati kapena wocheperako. Njira yake yogwirira ntchito ndi yofanana ndi mphambano ya PN, pamene phokoso la PIN likuwonekera ndi kuwala kwa kuwala, photon imasamutsira mphamvu ku electron, imapanga zonyamulira za photogenerated, ndi gawo lamagetsi lamkati kapena magetsi akunja adzalekanitsa chithunzithunzi cha photogenerated electron-hole. awiriawiri mu depletion wosanjikiza, ndi kutengeka chonyamulira mlandu kupanga panopa mu dera kunja. Udindo wa wosanjikiza I ndi kukulitsa m'lifupi mwa wosanjikiza kutha, ndi wosanjikiza ine kwathunthu kukhala wosanjikiza depletion pansi lalikulu kukondera voteji, ndi kwaiye ma elekitironi-bowo awiriawiri adzakhala mofulumira analekanitsidwa, kotero liwiro poyankha wa PIN junction photodetector nthawi zambiri imakhala yothamanga kuposa ya PN junction detector. Zonyamulira kunja kwa I wosanjikiza amasonkhanitsidwa ndi wosanjikiza depletion kudzera diffusion kuyenda, kupanga diffusion panopa. Makulidwe a I wosanjikiza nthawi zambiri amakhala woonda kwambiri, ndipo cholinga chake ndikuwongolera kuthamanga kwa chowunikira.

(4)APD Photodetectorchithunzi cha avalanche
Njira yachithunzi cha avalanchendi yofanana ndi ya PN mphambano. APD photodetector imagwiritsa ntchito kwambiri doped PN junction, voteji yogwiritsira ntchito potengera APD ndi yaikulu, ndipo pamene kukondera kwakukulu kumawonjezeredwa, kugunda kwa ionization ndi kuchulukitsa kwa avalanche kudzachitika mkati mwa APD, ndipo ntchito ya detector ikuwonjezeka photocurrent. Pamene APD ili mumsewu wotsitsimula, gawo lamagetsi muzitsulo zowonongeka lidzakhala lamphamvu kwambiri, ndipo zonyamulira za photogenerated zopangidwa ndi kuwala zidzalekanitsidwa mwamsanga ndipo mwamsanga zimagwedezeka pansi pa ntchito ya magetsi. Pali kuthekera kuti ma elekitironi adzagunda mu lattice panthawiyi, zomwe zimapangitsa kuti ma elekitironi mu lattice akhale ionized. Izi zimabwerezedwa, ndipo ma ion ionized mu latisi amawombana ndi lattice, zomwe zimapangitsa kuti chiwerengero cha zonyamulira mu APD chiwonjezeke, zomwe zimapangitsa kuti pakhale phokoso lalikulu. Ndi njira yapaderayi mkati mwa APD yomwe zowunikira zochokera ku APD nthawi zambiri zimakhala ndi mawonekedwe a liwiro loyankhira mwachangu, kupindula kwakukulu kwaposachedwa komanso kumva kwambiri. Poyerekeza ndi mphambano ya PN ndi PIN, APD ili ndi liwiro loyankha mwachangu, lomwe ndi liwiro lachangu kwambiri loyankhira pakati pa machubu amakono azithunzi.

(5) Schottky junction photodetector
Mapangidwe oyambira a Schottky junction photodetector ndi diode ya Schottky, yomwe mawonekedwe ake amagetsi ndi ofanana ndi a PN mphambano yomwe tafotokozera pamwambapa, ndipo imakhala ndi unidirectional conductivity yokhala ndi conduction yabwino komanso kudulidwa kumbuyo. Pamene chitsulo chokhala ndi ntchito yayikulu yogwira ntchito ndi semiconductor yokhala ndi mawonekedwe otsika a mawonekedwe a ntchito, chotchinga cha Schottky chimapangidwa, ndipo chigawo chotsatira ndi Schottky junction. Limagwirira chachikulu ndi penapake ofanana ndi PN mphambano, kutenga N-mtundu semiconductors mwachitsanzo, pamene zipangizo ziwiri kupanga kukhudzana, chifukwa cha ndende osiyana elekitironi wa zipangizo ziwiri, ma elekitironi mu semiconductor adzakhala diffuse ku mbali zitsulo. Ma elekitironi ogawanika amaunjikana mosalekeza kumapeto kwa chitsulo, motero amawononga kusalowerera ndale kwamagetsi kwachitsulo, kupanga malo opangira magetsi kuchokera ku semiconductor kupita kuzitsulo pamtunda wolumikizana, ndipo ma elekitironi adzayenda pansi pa zochita za gawo lamagetsi lamkati, ndipo kufalikira kwa chonyamulira ndi kusuntha kwamadzi kudzachitika nthawi imodzi, pakapita nthawi kuti ifike pamlingo wokhazikika, ndipo pamapeto pake kupanga mphambano ya Schottky. Pansi pa kuwala, chigawo chotchinga chimatenga kuwala mwachindunji ndikupanga ma electron-hole awiriawiri, pamene zonyamulira zojambulidwa mkati mwa PN mphumu zimayenera kudutsa m'dera la diffusion kuti zifike kudera la mphambano. Poyerekeza ndi mphambano ya PN, photodetector yochokera ku Schottky junction ili ndi liwiro lachangu, ndipo liwiro loyankhira likhoza kufika ngakhale mulingo wa ns.