Kapangidwe ka chowunikira zithunzi cha InGaAs

Kapangidwe kaChowunikira zithunzi cha InGaAs

Kuyambira m'zaka za m'ma 1980, ofufuza akunyumba ndi akunja akhala akuphunzira kapangidwe ka ma photodetector a InGaAs, omwe amagawidwa m'mitundu itatu. Ndi InGaAs metal-Semiconductor-metal photodetector (MSM-PD), InGaAs PIN Photodetector (PIN-PD), ndi InGaAs Avalanche Photodetector (APD-PD). Pali kusiyana kwakukulu pakupanga ndi mtengo wa ma photodetector a InGaAs okhala ndi mapangidwe osiyanasiyana, ndipo palinso kusiyana kwakukulu pakugwira ntchito kwa chipangizocho.

Chitsulo cha InGaAs-semiconductor-metalchowunikira zithunzi, yomwe yawonetsedwa pa Chithunzi (a), ndi kapangidwe kapadera kochokera pa Schottky junction. Mu 1992, Shi ndi anzake adagwiritsa ntchito ukadaulo wa epitaxy wachitsulo-organic vapor phase (LP-MOVPE) wochepa mphamvu kuti amere zigawo za epitaxy ndipo adakonza InGaAs MSM photodetector, yomwe ili ndi A high responseness ya 0.42 A/W pa wavelength ya 1.3 μm ndi mdima wamagetsi wotsika kuposa 5.6 pA/μm² pa 1.5 V. Mu 1996, zhang ndi anzake adagwiritsa ntchito gas phase molecular beam epitaxy (GSMBE) kuti amere gawo la InAlAs-InGaAs-InP epitaxy. Gawo la InAlAs linawonetsa mphamvu zodzitetezera kwambiri, ndipo mikhalidwe yokulira idakonzedwa bwino ndi muyeso wa X-ray diffraction, kotero kuti kusalingana kwa lattice pakati pa zigawo za InGaAs ndi InAlAs kunali mkati mwa 1×10⁻³. Izi zimapangitsa kuti chipangizo chigwire bwino ntchito ndi mphamvu yakuda pansi pa 0.75 pA/μm² pa 10 V komanso kuyankha mwachangu mpaka 16 ps pa 5 V. Ponseponse, chowunikira kapangidwe ka MSM ndi chosavuta komanso chosavuta kuphatikiza, kuwonetsa mphamvu yakuda yochepa (pA order), koma electrode yachitsulo imachepetsa malo ogwiritsira ntchito kuwala kwa chipangizocho, kotero kuyankhako kumakhala kotsika kuposa nyumba zina.

Chojambulira zithunzi cha InGaAs PIN chimayika gawo lamkati pakati pa gawo lolumikizirana la P-type ndi gawo lolumikizirana la N-type, monga momwe zasonyezedwera pa Chithunzi (b), chomwe chimawonjezera m'lifupi mwa dera lotha ntchito, motero chimayatsa mawiri ambiri a ma electron-hole ndikupanga photocurrent yayikulu, kotero chimakhala ndi magwiridwe antchito abwino kwambiri operekera ma electron. Mu 2007, A.Poloczek et al. adagwiritsa ntchito MBE kukulitsa gawo losungira kutentha kochepa kuti akonze kuuma kwa pamwamba ndikuthana ndi kusagwirizana kwa lattice pakati pa Si ndi InP. MOCVD idagwiritsidwa ntchito kuphatikiza kapangidwe ka InGaAs PIN pa gawo la InP, ndipo kuyankha kwa chipangizocho kunali pafupifupi 0.57A /W. Mu 2011, Army Research Laboratory (ALR) idagwiritsa ntchito zojambulira zithunzi za PIN kuti iphunzire chithunzi cha liDAR kuti chiyendetse, kupewa zopinga/kugundana, komanso kuzindikira/kuzindikira cholinga chapafupi kwa magalimoto ang'onoang'ono opanda anthu, ophatikizidwa ndi chip chotsitsa cha microwave chomwe chimathandizira kwambiri chiŵerengero cha chizindikiro-kwa-phokoso cha chithunzi cha InGaAs PIN. Pachifukwa ichi, mu 2012, ALR idagwiritsa ntchito chithunzi cha liDAR ichi pa maloboti, omwe ali ndi malo opitilira 50 m komanso resolution ya 256 × 128.

The InGaAschowunikira zithunzi cha chipale chofewandi mtundu wa chowunikira zithunzi chokhala ndi phindu, kapangidwe kake kakuwonetsedwa pa Chithunzi (c). Peyala ya ma electron-hole imapeza mphamvu zokwanira pansi pa mphamvu ya magetsi mkati mwa dera lowirikiza kawiri, kotero kuti igundane ndi atomu, kupanga ma electron-hole awiri atsopano, kupanga avalanche effect, ndikuchulukitsa zonyamulira zosalingana muzinthuzo. Mu 2013, George M adagwiritsa ntchito MBE kukulitsa ma lattice ofanana ndi InGaAs ndi InAlAs alloys pa gawo la InP, pogwiritsa ntchito kusintha kwa kapangidwe ka alloy, makulidwe a epitaxial layer, ndi doping ku mphamvu yonyamula yosinthidwa kuti iwonjezere electroshock ionization pomwe ikuchepetsa ionization ya mabowo. Pa phindu lofanana la chizindikiro chotulutsa, APD imawonetsa phokoso lochepa komanso mphamvu yamdima yotsika. Mu 2016, Sun Jianfeng ndi anzake adapanga seti ya nsanja yoyesera ya 1570 nm laser active imaging yochokera pa InGaAs avalanche photodetector. Dongosolo lamkati laChowunikira zithunzi cha APDMa echo olandiridwa ndi kutulutsa zizindikiro za digito mwachindunji, zomwe zimapangitsa chipangizo chonse kukhala chopapatiza. Zotsatira za kuyesa zikuwonetsedwa mu Chithunzi (d) ndi (e). Chithunzi (d) ndi chithunzi chenicheni cha cholinga chojambula, ndipo Chithunzi (e) ndi chithunzi cha mtunda wa magawo atatu. Zitha kuwoneka bwino kuti dera la zenera la dera c lili ndi mtunda wozama ndi dera A ndi b. Nsanjayo imazindikira kukula kwa pulse kosakwana 10 ns, mphamvu ya pulse imodzi (1 ~ 3) mJ yosinthika, gawo lolandira lens Angle ya 2°, kubwerezabwereza kwa 1 kHz, chiŵerengero cha detector duty cha pafupifupi 60%. Chifukwa cha kuchuluka kwa mkati mwa photocurrent kwa APD, kuyankha mwachangu, kukula kocheperako, kulimba komanso mtengo wotsika, ma photodetector a APD akhoza kukhala okwera kwambiri pakuzindikira kuposa ma PIN photodetector, kotero liDAR yayikulu yamakono imayang'aniridwa kwambiri ndi ma avalanche photodetectors.

Ponseponse, ndi chitukuko chachangu cha ukadaulo wokonzekera InGaAs kunyumba ndi kunja, titha kugwiritsa ntchito mwaluso MBE, MOCVD, LPE ndi ukadaulo wina kuti tikonzekere InGaAs epitaxial layer yapamwamba kwambiri pa InP substrate. InGaAs photodetectors imawonetsa mphamvu yakuda yochepa komanso kuyankha kwakukulu, mphamvu yakuda yotsika kwambiri ndi yotsika kuposa 0.75 pA/μm², kuyankha kwakukulu ndi mpaka 0.57 A/W, ndipo imakhala ndi yankho lachangu (ps order). Kukula kwamtsogolo kwa InGaAs photodetectors kudzayang'ana mbali ziwiri izi: (1) InGaAs epitaxial layer imakula mwachindunji pa substrate ya Si. Pakadali pano, zida zambiri zamagetsi zomwe zili pamsika zimachokera ku Si, ndipo chitukuko chotsatira cha InGaAs ndi Si ndicho chikhalidwe chachikulu. Kuthetsa mavuto monga kusalingana kwa lattice ndi kusiyana kwa kutentha kwa coefficient ndikofunikira kwambiri pakuphunzira InGaAs/Si; (2) Ukadaulo wa kutalika kwa mafunde a 1550 nm wakula, ndipo kutalika kwa mafunde (2.0 ~ 2.5) μm ndiye njira yofufuzira mtsogolo. Ndi kuwonjezeka kwa zigawo za In, kusagwirizana kwa lattice pakati pa gawo la InP ndi InGaAs epitaxial layer kudzatsogolera ku kusokonekera kwakukulu ndi zolakwika, kotero ndikofunikira kukonza magawo a njira ya chipangizocho, kuchepetsa zolakwika za lattice, ndikuchepetsa mphamvu yakuda ya chipangizocho.