Muma diode emagetsi anoburitsa chiedza (ma LED) eGaN-based, kufambira mberi kuri kuramba kuchiita mu epitaxial growth techniques uye magadzirirwo emidziyo kwakaita kuti internal quantum efficiency (IQE) iwedzere kusvika padanho rayo repamusoro. Pasinei nekufambira mberi uku, kushanda kwe LEDs kunoramba kuripo nekuda kwe light extraction efficiency (LEE). Sezvo sapphire ichiramba iri chinhu chinonyanya kukosha cheGaN epitaxy, chimiro chayo chepamusoro chinoita basa guru mukutonga kurasikirwa kwe optical mukati memudziyo.

Chinyorwa chino chinopa kuenzanisa kwakazara pakati pemasafire akapetwa uye mapatanizvigadziko zvesafiri (PSS)Inotsanangura mashandiro ekuona uye ekristaro ayo PSS inowedzera kushanda zvakanaka kwekuburitsa chiedza uye inotsanangura kuti nei PSS yave chiyero chaicho mukugadzira maLED ane mashandiro epamusoro.

1. Kushanda Nesimba Pakubvisa Chiedza Senzira Yekutanga Yekuderedza Kuwanda Kwezvinhu

Kubudirira kwekunze kwehuwandu hwe LED (EQE) kunotsanangurwa nechinhu chinobva pazvinhu zviviri zvikuru:

$EQE=IQE\times LEE\backslash text\{EQE\}\; =\; \backslash text\{IQE\}\; \backslash times\; \backslash text\{LEE\}$

EQE=IQE×LEE

Kunyange zvazvo IQE ichiyera kushanda kwe radiative recombination munzvimbo inoshanda, LEE inotsanangura chidimbu chemaphoton anogadzirwa anobuda mumudziyo zvinobudirira.

Kune ma LED akavakirwa paGaN anorimwa pamidziyo yesafire, LEE mumagadzirirwo emazuva ano inowanzo ganhurira kusvika pa30–40%. Muganho uyu unonyanya kubva pa:

• Kusawirirana kwakanyanya pakati peGaN (n ≈ 2.4), safira (n ≈ 1.7), uye mhepo (n ≈ 1.0)

• Kuratidzwa kwakasimba kwemukati menyika (TIR) ​​pa planar interfaces

• Kubata photon mukati mezvikamu zve epitaxial uye substrate

Nekuda kweizvozvo, chikamu chikuru chemaphoton anogadzirwa chinoonekwa mukati mechiedza kakawanda uye chinozopedzisira chatorwa nezvinhu zvacho kana kuchinjwa kuita kupisa pane kubatsira mukubuda kwechiedza.

2. Zvidimbu zveFlat Sapphire: Zviri nyore pakuvaka nekutarisa

2.1 Hunhu hweMaumbirwo

Zvigadziko zvesafire zvakati sandara zvinowanzoshandisa nzira ye c-plane (0001) ine pamusoro wakatsetseka, wakatsetseka. Zvave zvichishandiswa zvakanyanya nekuda kwe:

• Hunhu hwepamusoro hwekristaro

• Kugadzikana kwakanaka kwekupisa uye makemikari

• Maitiro ekugadzira akakura uye asingadhuri

2.2 Maitiro Ekuona

Kubva pakuona kwemaziso, ma planar interfaces anotungamira kunzira dzekupararira kwe photon dzinotungamira zvakanyanya uye dzinofanotaurwa. Kana ma photon akagadzirwa munzvimbo inoshanda yeGaN asvika paGaN-air kana GaN-sapphire interface pamakona ezviitiko anodarika angle yakakosha, kuratidzwa kwemukati kwese kunoitika.

Izvi zvinoguma ne:

• Kuvharirwa kwakasimba kwe photon mukati memuchina

• Kuwedzera kwekunyudzwa kwesimbi nemaerekitironi uye mamiriro ekuremara

• Kugoverwa kwakaganhurirwa kwechiedza chinoburitswa

Muchidimbu, zvinhu zvakaita sesafire substrates hazvibatsiri zvakanyanya pakukunda kuvharirwa kwemaziso.

3. Zvikamu zveSapphire zvine mapatani: Pfungwa uye Dhizaini yeChivako

Chinhu chinonzi patterned sapphire substrate (PSS) chinoumbwa nekuunza zvimiro zve periodic kana quasi-periodic micro- kana nanoscale pamusoro pesapphire uchishandisa nzira dzephotolithography uye etching.

Majometri akajairika ePSS anosanganisira:

• Zvivako zveConical

• Madhomu eHemispherical

• Zvinhu zvepiramidhi

• Maumbirwo e cylindrical kana kuti truncated-cone

Zviyero zvechishandiso zvinosiyana kubva pa-sub-micrometer kusvika kuma micrometer akati wandei, nekukwirira kwakanyatsorongwa, kukwirira, uye kutenderera kwebasa.

4. Nzira dzekuvandudza kuburitswa kwechiedza muPSS

4.1 Kudziviswa kweKufungisisa Kwemukati Kwese

Kugadzirwa kwePSS muzvikamu zvitatu kunochinja makona enzvimbo yechiitiko panzvimbo dzezvinhu. Maphotoni aizoona kuratidzwa kwemukati mese pamuganhu wakatwasuka anoendeswa kumakona ari mukati me escape cone, zvichiwedzera mukana wekubuda mumudziyo.

4.2 Kuwedzerwa Kupararira Kwemaziso uye Kusarongeka Kwenzira

Maumbirwo ePSS anounza zviitiko zvakawanda zvekusanzwisisa uye kufungisisa, zvichikonzera:

• Kusarongeka kwenzira dzekupararira kwe photon

• Kuwedzera kudyidzana neinterfaces dzekubvisa chiedza

• Nguva yekugara kwe photon yakaderedzwa mukati memudziyo

Maererano nehuwandu, izvi zvinowedzera mukana wekubviswa kwe photon usati wabatwa.

4.3 Kuyera Kushanda KweRefractive Index

Kubva pakuona kwe optical modeling, PSS inoshanda se refractive index transition layer inoshanda. Pane kuchinja kwe refractive index kubva kuGaN kuenda kumhepo, nzvimbo ine mapatani inopa shanduko ye refractive index zvishoma nezvishoma, nokudaro ichideredza kurasikirwa kweFresnel reflection.

Maitiro aya akafanana neanodzivirira kupenya, kunyange zvazvo achivimba ne geometric optics kwete kupindirana kwe thin-film.

4.4 Kuderedza Kurasikirwa Kwekunwa Maziso Nekusanangana

Nekupfupisa hurefu hwenzira ye photon uye kudzvinyirira kudzokorora kwemukati, PSS inoderedza mukana wekunyudzwa kwe optical ne:

• Kubata simbi

• Mamiriro ekukuvara kwekristaro

• Kunyudzwa kwemutakuri wemahara muGaN

Izvi zvinobatsira pakushanda zvakanaka uye kuvandudza mashandiro ekupisa.

5. Mamwe Mabhenefiti: Kuvandudzwa kweHunhu hweCrystal

Kupfuura kuwedzerwa kwemaziso, PSS inovandudzawo kunaka kwezvinhu zve epitaxial kuburikidza ne lateral epitaxial overgrowth (LEO) mechanisms:

• Kukanganisika kunobva pasapphire-GaN interface kunodzoserwa kana kugumiswa

• Kuwanda kwekutapurirana kweshinda kwakaderera zvakanyanya

• Hunhu hwekristaro hwakavandudzwa hunovandudza kuvimbika kwemudziyo uye hupenyu hwekushanda

Iyi nzira mbiri dzekutarisa uye dzekuvaka dzinosiyanisa PSS nenzira dzekutarisa pamusoro pechinhu chete.

6. Kuenzanisa kwehuwandu: Flat Sapphire vs. PSS

Kubudirira kwechokwadi pakushanda kunoenderana ne geometry yemapatani, urefu hwemhepo inobuda, dhizaini yemachipisi, uye nzira yekurongedza.

7. Kufunga Nezvekuchinjana uye Zvekugadzira Mainjiniya

Pasinei nezvakanakira zvayo, PSS inounza matambudziko akati wandei anoshanda:

• Mamwe matanho ekugadzira nekunyora anowedzera mutengo wekugadzira

• Kufanana kwemapatani uye kudzika kwemavara zvinoda kudzorwa kwakarurama

• Maitiro asina kunaka anogona kukanganisa kufanana kwe epitaxial

Saka, kugadzirisa PSS ibasa rine mabasa akawanda rinosanganisira kutevedzera optical, epitaxial growth engineering, uye dhizaini yemidziyo.

8. Maonero eIndasitiri uye Maonero eRemangwana

Mukugadzirwa kwe LED kwemazuva ano, PSS haichaonekwi sechinhu chinosarudzwa. Mukushandiswa kwe LED dzine simba repakati nepakati—kusanganisira kujekesa kwakajairika, kuvheneka kwemotokari, uye kuvheneka kumashure kwe display—yave tekinoroji yekutanga.

Mafambiro ekutsvaga nekuvandudza mune ramangwana anosanganisira:

• Magadzirirwo epamusoro ePSS akagadzirirwa maMini-LED nemaMicro-LED applications

• Nzira dzakasanganiswa dzinosanganisa PSS nemakristaro e photonic kana nanoscale surface texturing

• Kuenderera mberi nekuedza kuderedza mitengo uye matekinoroji ekugadzira mapatani anogona kukura

Mhedziso

Zvishandiso zvemasafire zvine mapatani zvinomiririra shanduko huru kubva pakutsigira kwemuchina usingashande kuenda kuzvinhu zvinoshanda zveoptical uye zvechimiro mumidziyo ye LED. Nekugadzirisa kurasikirwa kwekubviswa kwechiedza kubva pamudzi wazvo—kureva kuvharirwa kweoptical uye kuratidzwa kweinterface—PSS inoita kuti zvive nyore kushanda, kuvimbika kuri nani, uye kushanda zvakanaka kwemuchina.

Kusiyana neizvi, kunyange hazvo matanda esapphire akatsetseka achiramba achiyevedza nekuda kwekugadzirwa kwawo uye mutengo wakaderera, miganhu yawo yemaziso inodzikamisa kukodzera kwawo kune maLED echizvarwa chinotevera anoshanda zvakanyanya. Sezvo tekinoroji ye LED ichiramba ichichinja, PSS inomira semuenzaniso wakajeka wekuti mainjiniya ezvinhu anogona sei kushandura zvakananga mukubudirira kwesystem-level.