Li-photodetector le maqhubu a bolelele ba di-cutoff

Li-photodetectorsle maqhubu a ho qetela a bolelele ba maqhubu

Sengoloa sena se shebane le thepa le melao-motheo ea ts'ebetso ea li-photodetector (haholo-holo mokhoa oa karabelo o thehiloeng khopolo-taba ea sehlopha), hammoho le liparamente tsa bohlokoa le maemo a ts'ebeliso ea thepa e fapaneng ea semiconductor.
1. Molao-motheo oa mantlha: Photodetector e sebetsa ho latela phello ea photoelectric. Li-photon tse etsahalang li hloka ho jara matla a lekaneng (a fetang bophara ba bandgap Eg ea thepa) ho tsosa lielektrone ho tloha sehlopheng sa valence ho ea sehlopheng sa conduction, ho etsa lets'oao la motlakase le ka bonoang. Matla a photon a lekana ka tsela e fapaneng le bolelele ba leqhubu, kahoo sesebelisoa se na le "leqhubu la leqhubu le khaotsoeng" (λ c) - bolelele ba leqhubu bo boholo bo ka arabelang, boo ho feta moo bo ke keng ba arabela ka katleho. Leqhubu la leqhubu le khaotsoeng le ka hakanngoa ho sebelisoa foromo λ c ≈ 1240/Eg (nm), moo Eg e lekanngoang ka eV.
2. Lisebelisoa tsa bohlokoa tsa semiconductor le litšobotsi tsa tsona:
Silicon (Si): bophara ba leqhubu la bandgap bo ka bang 1.12 eV, bolelele ba leqhubu bo ka bang 1107 nm. E loketse ho lemoha bolelele ba leqhubu bo bokhutšoanyane bo kang 850 nm, e sebelisoang hangata bakeng sa khokahano ea fiber optic ea nako e khuts'oane (joalo ka litsi tsa data).
Gallium arsenide (GaAs): bophara ba leqhubu la leqhubu la 1.42 eV, bolelele ba leqhubu bo ka bang 873 nm. E loketse leqhubu la leqhubu la 850 nm, e ka kopanngwa le mehlodi ya mabone ya VCSEL ya thepa e tshwanang hodima chip e le nngwe.
Indium gallium arsenide (InGaAs): Bophara ba lekhalo la leqhubu bo ka fetoloa pakeng tsa 0.36 ~ 1.42 eV, 'me bolelele ba leqhubu bo koahelang 873 ~ 3542 nm. Ke thepa e ka sehloohong ea ho lemoha lifensetere tsa puisano tsa faeba tsa 1310 nm le 1550 nm, empa e hloka substrate ea InP 'me e rarahane ho kopanngoa le lipotoloho tse thehiloeng ho silicon.
Germanium (Ge): e na le bophara ba leqhubu la bandgap ba hoo e ka bang 0.66 eV le bolelele ba wavelength ba cutoff ba hoo e ka bang 1879 nm. E ka koahela 1550 nm ho isa ho 1625 nm (L-band) mme e tsamaisana le di-substrate tsa silicon, e leng se etsang hore e be tharollo e ka khonehang bakeng sa ho atolosa karabelo ho di-band tse telele.
Motsoako oa silicon germanium (joalo ka Si0.5Ge0.5): bophara ba lekhalo la bandgap bo ka bang 0.96 eV, bolelele ba leqhubu ba cutoff bo ka bang 1292 nm. Ka ho sebelisa germanium ka har'a silicon, bolelele ba leqhubu la karabelo bo ka atolosoa ho lihlopha tse telele holim'a substrate ea silicon.
3. Kamano ea maemo a ts'ebeliso:
Sehlopha sa 850 nm:Lisebelisoa tsa ho lemoha litšoantšo tsa siliconkapa di-photodetector tsa GaAs di ka sebediswa.
Sehlopha sa 1310/1550 nm:Li-photodetector tsa InGaAsdi sebediswa haholoholo. Di-photodetector tse hlwekileng tsa germanium kapa silicon germanium alloy le tsona di ka akaretsa mefuta ena mme tsa ba le melemo e ka bang teng ho kopantsweng ho itshetlehileng hodima silicon.

Ka kakaretso, ka mehopolo ea mantlha ea khopolo-taba ea sehlopha le bolelele ba maqhubu a khaotsoeng, litšobotsi tsa ts'ebeliso le mefuta e fapaneng ea likhakanyo tsa maqhubu a lisebelisoa tse fapaneng tsa semiconductor ho li-photodetector li hlahlobiloe ka mokhoa o hlophisitsoeng, 'me kamano e haufi pakeng tsa khetho ea thepa, fensetere ea bolelele ba maqhubu a puisano ea fiber optic, le litšenyehelo tsa ts'ebetso ea kopanyo li se li bontšitsoe.