Isishwankathelo: Ulwakhiwo olusisiseko kunye nomgaqo wokusebenza we-avalanche photodetector (Isixhobo sokubona ifoto se-APD) ziyaziswa, inkqubo yokuvela kwesakhiwo sesixhobo iyahlalutywa, imeko yophando lwangoku iyashwankathelwa, kwaye uphuhliso lwexesha elizayo lwe-APD lufundwa ngendlela ecwangcisiweyo.
1. Intshayelelo
Isixhobo sokufumana ukukhanya sisixhobo esiguqula imiqondiso yokukhanya ibe yimiqondiso yombane.isixhobo sokubona ifoto se-semiconductor, isithwali esenziwe ngefoto esivuselelwe yi-incident photon singena kwisekethe yangaphandle phantsi kwe-applied bias voltage kwaye senze i-photocurrent enokulinganiswa. Nokuba kuphendula kakhulu, i-PIN photodiode inokuvelisa kuphela isibini see-electron-hole pairs kuphela, esisixhobo esingenanzuzo yangaphakathi. Ukuze siphendule ngakumbi, i-avalanche photodiode (APD) ingasetyenziswa. Isiphumo sokukhulisa se-APD kwi-photocurrent sisekelwe kwisiphumo sokungqubana kwe-ionization. Phantsi kweemeko ezithile, ii-electron ezikhawulezileyo kunye neengxunya zinokufumana amandla aneleyo okungqubana ne-lattice ukuvelisa isibini esitsha see-electron-hole pairs. Le nkqubo yi-chain reaction, ukuze isibini see-electron-hole pairs eziveliswe kukufunxwa kokukhanya zivelise inani elikhulu lee-electron-hole pairs kwaye zenze i-photocurrent enkulu yesibini. Ke ngoko, i-APD inokuphendula okuphezulu kunye nenzuzo yangaphakathi, nto leyo ephucula umlinganiselo wesignali-kwingxolo yesixhobo. I-APD iya kusetyenziswa ikakhulu kwiinkqubo zonxibelelwano lwe-optical fiber ezikude okanye ezincinci ezineminye imida kumandla okukhanya afunyenweyo. Okwangoku, iingcali ezininzi zezixhobo ze-optical zinethemba elikhulu ngamathuba e-APD, kwaye zikholelwa ukuba uphando lwe-APD luyimfuneko ukuphucula ukhuphiswano lwamazwe ngamazwe kwiinkalo ezinxulumene noko.
2. Uphuhliso lobugcisa lweisixhobo sokubona ifoto se-avalanche(Isixhobo sokubona ifoto se-APD)
2.1 Izixhobo
(1)Isixhobo sokubona ifoto
Itekhnoloji yezinto ezibonakalayo ye-Si yitekhnoloji evuthiweyo esetyenziswa kakhulu kwicandelo le-microelectronics, kodwa ayifanelekanga ukulungiselela izixhobo ezikuluhlu lwamaza oluyi-1.31mm kunye ne-1.55mm ezamkelwa ngokubanzi kwicandelo lonxibelelwano lwe-optical.
(2)Ge
Nangona impendulo ye-spectral ye-Ge APD ifanelekile kwiimfuno zokulahleka okuphantsi kunye nokusasazeka okuphantsi kwi-optical fiber transmission, kukho ubunzima obukhulu kwinkqubo yokulungiselela. Ukongeza, umlinganiselo we-electron kunye ne-hole ionization rate kaGe usondele kwi-() 1, ngoko ke kunzima ukulungiselela izixhobo ze-APD ezisebenza kakuhle.
(3)Kwi-0.53Ga0.47As/InP
Yindlela esebenzayo yokukhetha i-In0.53Ga0.47Njengomaleko wokufunxa ukukhanya we-APD kunye ne-InP njengomaleko wokuphindaphinda. Incopho yokufunxa yezinto ze-In0.53Ga0.47As yi-1.65mm, ubude bayo obuyi-1.31mm, 1.55mm bumalunga ne-104cm-1 high absorption coefficient, eyiyeyona nto ikhethwayo kumaleko wokufunxa wesixhobo sokukhanya okwangoku.
(4)Isixhobo sokubona iifoto se-InGaAs/Ngaphakathiisixhobo sokubona iifoto
Ngokukhetha i-InGaAsP njengomaleko ofunxa ukukhanya kunye ne-InP njengomaleko wokuphindaphinda, i-APD enobude be-response obuyi-1-1.4mm, ukusebenza kakuhle kwe-quantum, umbane omnyama ophantsi kunye nokunyuka okuphezulu kwe-avalanche kunokulungiswa. Ngokukhetha izinto ezahlukeneyo ze-alloy, ukusebenza okungcono kakhulu kwii-wavelengths ezithile kuyafezekiswa.
(5)Ii-InGaAs/Ii-InAlAs
Izinto ze-In0.52Al0.48As zinesithuba sebhendi (1.47eV) kwaye azifunxi kuluhlu lwamaza oluyi-1.55mm. Kukho ubungqina bokuba umaleko omncinci we-In0.52Al0.48As epitaxial unokufumana iimpawu zokufumana ezingcono kune-InP njengomaleko wokuphindaphinda phantsi kwemeko yokufakwa kwe-electron ecocekileyo.
(6)Ii-InGaAs/InGaAs (P) /InAlAs kunye nee-InGaAs/In (Al) GaAs/InAlAs
Izinga le-ionization yempembelelo yezinto liyinto ebalulekileyo echaphazela ukusebenza kwe-APD. Iziphumo zibonisa ukuba izinga le-ionization yokungqubana komaleko wokuphindaphinda linokuphuculwa ngokwazisa izakhiwo ze-InGaAs (P) /InAlAs kunye ne-In (Al) GaAs/InAlAs superlattice. Ngokusebenzisa isakhiwo se-superlattice, ubunjineli bebhendi bunokulawula ngokwenziwa ukungahambelani komphetho webhendi phakathi kwebhendi yokuqhuba kunye namaxabiso ebhendi ye-valence, kwaye buqinisekise ukuba ukungahambelani kwebhendi yokuqhuba kukhulu kakhulu kunokungahambelani kwebhendi ye-valence (ΔEc>>ΔEv). Xa kuthelekiswa nezinto ze-InGaAs ezininzi, izinga le-ionization ye-electron ye-InGaAs/InAlAs ye-quantum well (a) liyanda kakhulu, kwaye ii-electron kunye neengxunya zifumana amandla ongezelelweyo. Ngenxa ye-ΔEc>>ΔEv, kunokulindeleka ukuba amandla afunyenwe zii-electron anyusa izinga le-ionization ye-electron ngaphezulu kakhulu kunegalelo lamandla emingxunya kwizinga le-ionization yemingxunya (b). Umlinganiselo (k) wezinga le-ionization ye-electron kwizinga le-ionization yemingxunya uyanda. Ngoko ke, imveliso ye-gain-bandwidth ephezulu (GBW) kunye nokusebenza kwengxolo ephantsi kunokufumaneka ngokusebenzisa izakhiwo ze-superlattice. Nangona kunjalo, olu lwakhiwo lwe-quantum well APD lwe-InGaAs/InAlAs, olunokunyusa ixabiso le-k, kunzima ukulusebenzisa kwi-optical receivers. Oku kungenxa yokuba into yokuphindaphinda echaphazela ukuphendula okuphezulu inqunyelwe yi-dark current, hayi yingxolo yokuphindaphinda. Kule sakhiwo, i-dark current ibangelwa kakhulu yi-tunneling effect ye-InGaAs well layer ene-band gap encinci, ngoko ke ukungeniswa kwe-wide-band gap quaternary alloy, efana ne-InGaAsP okanye i-InAlGaAs, endaweni ye-InGaAs njengoluhlu lwe-well lwesakhiwo se-quantum well kunokucinezela i-dark current.
Ixesha lokuthumela: Novemba-13-2023