Kuma-diode akhipha ukukhanya (ama-LED) asekelwe ku-GaN, intuthuko eqhubekayo kumasu okukhula kwe-epitaxial kanye nokwakhiwa kwedivayisi kuye kwaholela ekusebenzeni kahle kwe-quantum yangaphakathi (IQE) eduze kakhulu nobukhulu bayo bethiyori. Naphezu kwalokhu kuthuthuka, ukusebenza okukhanyayo okuphelele kwama-LED kusalokhu kunqunyelwe ngokuyisisekelo ukusebenza kahle kokukhipha ukukhanya (i-LEE). Njengoba i-sapphire iqhubeka nokuba yizinto eziyinhloko ze-epitaxy ye-GaN, ukuma kwayo kobuso kudlala indima ebalulekile ekulawuleni ukulahlekelwa kokukhanya ngaphakathi kwedivayisi.

Lesi sihloko sinikeza ukuqhathanisa okuphelele phakathi kwe-flat sapphire substrates kanye ne-patternedizisekelo zesafire (i-PSS)Icacisa izindlela zokukhanya kanye ne-crystallographic lapho i-PSS ithuthukisa khona ukusebenza kahle kokukhipha ukukhanya futhi ichaza ukuthi kungani i-PSS isibe yindinganiso yangempela ekukhiqizweni kwe-LED esebenza kahle kakhulu.

1. Ukusebenza Kahle Kokukhipha Ukukhanya Njengesivikelo Esiyisisekelo

Ukusebenza kahle kwe-quantum yangaphandle (i-EQE) ye-LED kunqunywa umkhiqizo wezici ezimbili eziyinhloko:

$I-EQE=IQE\times LEE\backslash umbhalo\{EQE\}\; =\; \backslash umbhalo\{IQE\}\; \backslash izikhathi\; \backslash umbhalo\{LEE\}$

I-EQE=IQE×LEE

Ngenkathi i-IQE ilinganisa ukusebenza kahle kokuhlanganiswa kwemisebe ngaphakathi kwesifunda esisebenzayo, i-LEE ichaza ingxenye yama-photon akhiqizwe aphuma ngempumelelo kudivayisi.

Kuma-LED asekelwe ku-GaN akhuliswe kuma-substrate e-sapphire, i-LEE kumiklamo evamile ivame ukukhawulelwa cishe ku-30–40%. Lo mkhawulo uvela ngokuyinhloko ku:

• Ukungafani okukhulu kwenkomba yokubuyisa phakathi kwe-GaN (n ≈ 2.4), i-sapphire (n ≈ 1.7), kanye nomoya (n ≈ 1.0)

• Ukubonakaliswa kwangaphakathi okuqinile (i-TIR) ezindaweni zokuhlangana ezihleliwe

• Ukubanjwa kwe-Photon ngaphakathi kwezingqimba ze-epitaxial kanye ne-substrate

Ngenxa yalokho, ingxenye enkulu yama-photon akhiqiziwe idlula ekukhanyeni kwangaphakathi okuningi futhi ekugcineni imuncwa yizinto noma iguqulwe ibe ukushisa esikhundleni sokufaka isandla ekukhanyeni okuwusizo.

2. Izingxenyana Ze-Flat Sapphire: Ubulula Besakhiwo Nezithiyo Zokubona

2.1 Izici Zesakhiwo

Izakhiwo ze-sapphire ezisicaba ngokuvamile zisebenzisa ukuma kwe-c-plane (0001) okunobuso obubushelelezi nobucwebezelayo. Ziye zamukelwa kabanzi ngenxa yalokhu:

• Ikhwalithi ephezulu yekristalu

• Ukuqina okuhle kakhulu kokushisa namakhemikhali

• Izinqubo zokukhiqiza ezivuthiwe nezingabizi kakhulu

2.2 Ukuziphatha Kokubona

Kusukela embonweni wokukhanya, izixhumi ezihleliwe ziholela ezindleleni zokusabalala kwe-photon eziqondisa kakhulu futhi ezibikezelwayo. Lapho ama-photon akhiqizwa esifundeni esisebenzayo se-GaN efika esixhumi esibonakalayo se-GaN–air noma se-GaN–sapphire kuma-engeli esigameko adlula i-engeli ebalulekile, ukubonakaliswa kwangaphakathi okuphelele kwenzeka.

Lokhu kuphumela ku:

• Ukuvalelwa kwe-photon okuqinile ngaphakathi kwedivayisi

• Ukumuncwa okwandisiwe yi-electrode yensimbi kanye nezimo zokukhubazeka

• Ukusatshalaliswa okulinganiselwe kwe-angle kokukhanya okukhishwe

Empeleni, ama-substrate e-flat sapphire awanikezi usizo oluncane ekunqobeni ukuvalelwa kwamehlo.

3. Izingxenyana Zesafire Ezinephethini: Umqondo Nomklamo Wesakhiwo

I-substrate ye-sapphire enephethini (i-PSS) yakhiwa ngokwethula izakhiwo ezincane noma ezincane ezihlala isikhathi eside noma ezihlala isikhathi eside ebusweni be-sapphire kusetshenziswa amasu e-photolithography kanye nokusika.

Amajiyometri avamile e-PSS afaka:

• Izakhiwo ezimise okwekhoni

• Ama-domes angaphansi komhlaba

• Izici ze-pyramidal

• Izimo ze-cylindrical noma ze-cuncated-cone

Ubukhulu besici obujwayelekile busukela ku-sub-micrometer kuya kuma-micrometer amaningana, ngokuphakama okulawulwa ngokucophelela, iphimbo, kanye nomjikelezo womsebenzi.

4. Izindlela Zokuthuthukisa Ukukhishwa Kokukhanya ku-PSS

4.1 Ukucinywa Kokuzindla Kwangaphakathi Okuphelele

I-topography ye-PSS enezinhlangothi ezintathu iguqula ama-engeli endawo okwenzeka kwawo ezindaweni ezibonakalayo. Ama-photon abengabhekana nokubonakaliswa kwangaphakathi okuphelele emngceleni oyisicaba aqondiswa kabusha abe ama-engeli ngaphakathi kwekhoni yokuphunyuka, okwandisa kakhulu amathuba awo okuphuma kudivayisi.

4.2 Ukuthuthukiswa Kokusabalalisa Okubonakalayo kanye Nokungahleliwe Kwendlela

Izakhiwo ze-PSS zethula izehlakalo eziningi zokucasuka kanye nokuzindla, okuholela ku:

• Ukungahleliwe kwezikhombisi-ndlela zokusabalala kwe-photon

• Ukuxhumana okwandisiwe nezixhumi zokukhipha ukukhanya

• Isikhathi sokuhlala se-photon esincishisiwe ngaphakathi kwedivayisi

Ngokwezibalo, le miphumela ikhulisa amathuba okukhishwa kwe-photon ngaphambi kokuba kungene.

4.3 Ukuhlolwa Kwenkomba Yokubheka Okusebenzayo

Kusukela embonweni wokwenza imodeli ye-optical, i-PSS isebenza njengesendlalelo sokushintsha kwenkomba ye-refractive esisebenzayo. Esikhundleni sokushintsha kwenkomba ye-refractive ngokuzumayo kusuka ku-GaN kuya emoyeni, isifunda esinamaphethini sinikeza ukushintshashintsha kwenkomba ye-refractive kancane kancane, ngaleyo ndlela kunciphisa ukulahleka kokubonakaliswa kwe-Fresnel.

Le ndlela yokusebenza ifana ngokomqondo nezingubo ezilwa nokukhanya, yize incike ku-geometric optics kunokuphazamiseka kwefilimu encane.

4.4 Ukunciphisa Okungaqondile Kokulahlekelwa Kokumuncwa Kwamehlo

Ngokufinyeza ubude bendlela ye-photon nokucindezela ukubonakaliswa kwangaphakathi okuphindaphindiwe, i-PSS inciphisa amathuba okumuncwa kokukhanya ngokuthi:

• Ukuxhumana kwensimbi

• Izimo zokukhubazeka kwekristalu

• Ukumuncwa kwe-Free-carrier ku-GaN

Le miphumela inegalelo ekusebenzeni kahle okuphezulu kanye nokusebenza kahle kokushisa.

5. Izinzuzo Ezengeziwe: Ukuthuthukiswa Kwekhwalithi Yekristalu

Ngale kokuthuthukiswa kokukhanya, i-PSS iphinde ithuthukise ikhwalithi yezinto ze-epitaxial ngokusebenzisa izindlela zokukhula ngokweqile kwe-lateral epitaxial (LEO):

• Ukususwa okuvela esibonakalayo se-sapphire-GaN kuyaqondiswa kabusha noma kuqedwe

• Ubuningi bokuhlukaniswa kwentambo buncishisiwe kakhulu

• Ikhwalithi yekristalu ethuthukisiwe ithuthukisa ukuthembeka kwedivayisi kanye nesikhathi sokusebenza kwayo

Le nzuzo ekabili yokukhanya kanye nesakhiwo ihlukanisa i-PSS nezindlela zokwakheka kobuso ezibonakala kuphela.

6. Ukuqhathanisa Okulinganiselwe: I-Flat Sapphire vs. PSS

Izinzuzo zangempela zokusebenza zincike ku-geometry yephethini, ubude besikhathi sokukhishwa kwe-emission, ukwakheka kwe-chip, kanye nesu lokupakisha.

7. Ukucatshangelwa Kokushintshana Nobunjiniyela

Naphezu kwezinzuzo zayo, i-PSS yethula izinselele eziningana ezisebenzayo:

• Izinyathelo ezengeziwe ze-lithography kanye ne-etching zandisa izindleko zokukhiqiza

• Ukufana kwephethini kanye nokujula kwe-etch kudinga ukulawulwa okunembile

• Amaphethini alungiselelwe kabi angathinta kabi ukufana kwe-epitaxial

Ngakho-ke, ukulungiswa kwe-PSS ngokwemvelo kuwumsebenzi wezifundo eziningi ohilela ukulingisa okubonakalayo, ubunjiniyela bokukhula kwe-epitaxial, kanye nomklamo wamadivayisi.

8. Umbono Wemboni kanye Nombono Wesikhathi Esizayo

Ekwenzeni i-LED yesimanje, i-PSS ayisabhekwa njengento yokuthuthukisa ongayikhetha. Ezinhlelweni ze-LED ezinamandla aphakathi naphezulu—kufaka phakathi ukukhanya okuvamile, ukukhanyisa kwezimoto, kanye nokukhanyisa okubonakalayo—sekuyibuchwepheshe obuyisisekelo.

Ucwaningo lwesikhathi esizayo kanye nezindlela zokuthuthukiswa zifaka:

• Imiklamo ye-PSS ethuthukisiwe eyenzelwe izinhlelo zokusebenza ze-Mini-LED kanye ne-Micro-LED

• Izindlela ze-hybrid ezihlanganisa i-PSS namakristalu e-photonic noma ukuthungwa kobuso obuncane

• Imizamo eqhubekayo yokunciphisa izindleko kanye nobuchwepheshe bokwenza amaphethini obungakhula

Isiphetho

Ama-substrate e-sapphire anephethini amelela ushintsho oluyisisekelo oluvela ezisekelweni zemishini ezingasebenzi kuya ezingxenyeni ezisebenzayo ze-optical nezesakhiwo kumadivayisi e-LED. Ngokubhekana nokulahlekelwa kokukhishwa kokukhanya ezimpandeni zawo—okungukuthi ukuvalelwa kwe-optical kanye nokubonakaliswa kwe-interface—i-PSS inika amandla okusebenza kahle okuphezulu, ukuthembeka okuthuthukisiwe, kanye nokusebenza kwedivayisi okuhlala njalo.

Ngokuphambene nalokho, yize ama-substrate e-sapphire ayisicaba ehlala ekhangayo ngenxa yokukhiqizwa kwawo kanye nezindleko eziphansi, ukulinganiselwa kwawo okubonakalayo okungokwemvelo kuvimbela ukufaneleka kwawo kuma-LED esizukulwane esilandelayo asebenza kahle kakhulu. Njengoba ubuchwepheshe be-LED buqhubeka nokukhula, i-PSS iyisibonelo esicacile sendlela ubunjiniyela bezinto obungahumushela ngayo ngqo ezinzuzweni zokusebenza ezingeni lesistimu.