Tsarin Abubuwan Ciki
1. Gabatarwa & Bayyani
Micro-Light Emitting Diodes (Micro-LEDs) na tushen Gallium Nitride (GaN) suna da muhimmanci ga nuni na zamani na gaba, ƙari/duniyar gaske (AR/VR), da sadarwar haske mai gani. Duk da haka, yayin da girman na'ura ya ragu zuwa ma'aunin micrometer, suna fama da "tasirin girman inganci," inda sake haɗuwa da saman da ba na walƙiya ba ke rage ingancin haske sosai. Wannan binciken ya gabatar da sabon mafita: haɗa layer guda na porous GaN a ƙarƙashin yankin aiki. Wannan tsarin yana haɓaka tsarewar haske kuma yana gyara fitowar kai tsaye, wanda ke haifar da haɓaka mai ban mamaki na kusan sau 22 a cikin ƙarfin haske da kuma rage faɗin bakan fitowar haske, musamman a cikin siffofi na mesa na polygonal.
2. Fasaha ta Tsakiya & Hanyoyin Aiki
2.1 Tsarin Na'ura & Ƙirƙira
An ƙirƙira na'urorin ta amfani da tsarin epitaxial na LED kore da aka gyara. Wani sabon abu mai mahimmanci shine haɗa layer na n-GaN mai yawan doping a ƙasa da InGaN/GaN multiple quantum wells (MQWs). Daga baya an canza wannan layer zuwa layer na porous GaN ta hanyar etching na electrochemical. Wannan tsari yana haifar da hanyar sadarwa na nano-pores, yana rage ingantaccen refractive index na layer. Idan aka kwatanta da rikitattun tarin Distributed Bragg Reflector (DBR), wannan hanyar layer guda tana sauƙaƙa ƙirƙira kuma tana amfana da gudanar da wutar lantarki na tsayi.
2.2 Matsayin Layer na Porous
Layer na porous yana aiki azaman yanki mai ƙarancin index, yana haifar da bambanci a cikin refractive index tare da GaN da ke kewaye. Wannan bambanci yana haɓaka tsarewar haske na gefe a cikin yankin aiki, yana rage zubewar haske kuma yana jagorantar photons mafi inganci zuwa saman fitowar haske na sama. Tsarin yana kama da ƙirƙirar waveguide na gani na ciki, wanda ke haɓaka yuwuwar cirewar photon.
2.3 Bambance-bambancen Siffar Mesa
Binciken ya binciki na'urori tare da siffofi na mesa na madauwari, murabba'i, da hexagonal. Ana tunanin cewa siffofi na polygonal (murabba'i da hexagon) suna tallafawa mafi kyawun yanayin resonant na gani saboda bangon gefensu masu fuska, waɗanda zasu iya zama masu nuna rauni, suna ƙara haɓaka hulɗar haske-da-kwayoyin halitta a cikin micro-cavity da aka kafa ta mesa da layer na porous.
Ma'auni Mai Muhimmanci na Aiki
22x
Haɓaka Ƙarfin Hasken Walƙiya
Siffa Mai Muhimmanci
Layer Guda
Tsarin Porous (vs. DBR Mai Yawan Layer)
3. Sakamakon Gwaji & Bincike
3.1 Haɓaka Ƙarfin Hasken Walƙiya
Sakamako mafi ban mamaki shine haɓakar ƙarfin haske kusan sau 22 ga Micro-LEDs tare da layer na porous idan aka kwatanta da takwarorinsu marasa porous. Wannan yana magance matsalar tsakiya na tasirin girman inganci kai tsaye, yana tabbatar da ingancin layer na porous wajen dawo da fitowar haske daga ƙananan na'urori.
3.2 Rage Faɗin Layin Bakan Hasken
An lura da raguwa mai mahimmanci a cikin Cikakken Faɗi a Rabin Matsakaici (FWHM) na bakan fitowar haske, musamman a cikin na'urori na polygonal. Wannan raguwa yana nuna sauyawa daga fitowar kai tsaye kawai zuwa yanayin da ke da tasirin resonant cavity, inda ake fifita takamaiman yanayin gani, wanda ke haifar da fitowar haske mafi tsafta a bakan. Wannan yana da mahimmanci ga aikace-aikacen nuni waɗanda ke buƙatar tsaftar launi mai girma.
3.3 Aikin Da Ya Dogara da Siffa
Bayanan gwaji sun bayyana cewa Micro-LEDs na porous na murabba'i da hexagonal sun nuna halayen fitowar resonant mafi bayyananne fiye da na madauwari. Kusurwoyi masu kaifi da gefuna madaidaici na polygons suna yiwuwa suna ba da ingantaccen amsa na gani, suna tallafawa Yanayin Zauren Whispers ko wasu resonances na cavity waɗanda ke haɓaka jagorancin fitarwa da sarrafa bakan.
4. Cikakkun Bayanai na Fasaha & Tsarin Lissafi
Ana iya fahimtar haɓakar wani ɓangare ta hanyar tsarewar gani ($\Gamma$) da la'akari da tasirin Purcell. Layer na porous yana gyara ingantaccen bayanin refractive index, yana ƙara ma'aunin tsarewar gefe don yanayin a cikin yankin aiki. Factor Purcell ($F_p$), wanda ke bayyana gyaran ƙimar fitowar kai tsaye a cikin cavity, ana bayar da shi kamar haka:
$F_p = \frac{3}{4\pi^2} \left(\frac{\lambda}{n}\right)^3 \frac{Q}{V_{mode}}$
Inda $\lambda$ shine tsawon zangon fitowar haske, $n$ shine refractive index, $Q$ shine ma'aunin inganci, kuma $V_{mode}$ shine ƙarar modal. Mesa na polygonal tare da layer na porous yana ƙara yuwuwar ƙara $Q$ (saboda ingantaccen tsarewa) kuma yana rage $V_{mode}$, wanda ke haifar da ƙaruwar $F_p$ don haka sauri, mafi inganci fitowar kai tsaye. Rage bakan yana da alaƙa kai tsaye da haɓakar $Q$-factor na cavity.
5. Tsarin Bincike & Misalin Lamari
Tsarin Don Kimanta Dabarun Haɓaka Micro-LED:
- Gano Matsala: Ƙididdige tasirin girman inganci (misali, ingantaccen ingancin quantum na waje vs. yankin mesa).
- Tsarin Magani: Rarraba hanyar: Passivation na Surface, Crystal na Photonic, Resonant Cavity (DBR, Layer na Porous), Waveguide.
- Ma'auni Mai Muhimmanci: Ayyana abubuwan da ake iya aunawa: Ƙarfin Hasken Walƙiya (cd/A), EQE (%), FWHM (nm), Kallon Kallo.
- Rikitarwar Ƙirƙira: Kimanta matakan tsari, haƙurin daidaitawa, da dacewa da samarwa mai yawa.
- Girma & Haɗawa: Kimanta yuwuwar mafita don tsararrun pixel masu yawa da nuni mai cikakken launi.
Aikace-aikacen Lamari: Yin amfani da wannan tsarin ga aikin da aka gabatar: Maganin layer na porous yana samun maki mai girma akan magance matsalar tsakiya (riba mai ƙarfi 22x) da sauƙaƙa ƙirƙira (layer guda vs. DBR). Girman sa don micro-displays na RGB yana buƙatar ƙarin bincike akan etching na porous da ya dogara da tsawon zango da daidaiton allurar wutar lantarki.
6. Muhimman Fahimta & Ra'ayi na Mai Bincike
Fahimta ta Tsakiya: Wannan ba kawai haɓakar inganci ba ne; yana da mahimmanci daga rikitattun DBRs masu nauyin epitaxy zuwa mafi sauƙi, tsarin photonic da aka ayyana ta hanyar etching. Ribar 22x tana nuna cewa sarrafa zubewar photon na gefe yana da mahimmanci kamar cirewar tsaye ga ƙananan LED. Cikakken nasara shine cimma tasirin kamar resonant-cavity (rage FWHM) ba tare da cavity mai yawan layer ba, yana ƙalubalantar akidar ƙira da ta mamaye fagen.
Tsarin Hankali: Hankalin binciken yana da kyau: gano raguwar inganci da girman ya haifar → yi hasashen cewa tsarewar haske na gefe shine mabuɗin toshewa → aiwatar da layer na porous mai ƙarancin index azaman shinge na gani na gefe → tabbatar da shi tare da ma'auni na ƙarfi da bakan. Binciken siffa shine mataki na gaba na hankali don bincika tasirin cavity.
Ƙarfi & Kurakurai: Ƙarfin ba shakka yana cikin ma'aunin aikin sa da sauƙin ƙirƙira, mai kama da yadda mafita masu rushewa sukan fito daga sauƙaƙa rikitattun tsarin da suka wanzu (misali, sauyawa daga rikitattun ƙwayoyin hasken rana na multi-junction zuwa ƙirar perovskite single-junction). Duk da haka, manyan kurakurai suna ci gaba. Takardar ba ta da maganar halayen lantarki: menene tasirin akan ƙarfin lantarki na gaba, zubewar wutar lantarki, ko amincin? Semiconductor na porous na iya zama sananne don ƙara sake haɗuwa mara walƙiya a saman pores idan ba a cika shi ba. Bugu da ƙari, kwanciyar hankali na dogon lokaci na waɗannan tsarin nano-porous a ƙarƙashin aiki mai yawan wutar lantarki—wanda ya zama dole don nuni—ba a magance shi gaba ɗaya ba. Aikin kuma ya rasa kwatanta kai tsaye tare da RCLED na zamani na tushen DBR akan ma'auni masu mahimmanci kamar ingancin toshewar bango.
Fahimta Mai Aiki: Ga masu kera nuni, wannan yanki ne na tsari mai ban sha'awa da ya cancanci gwaji. Mataki na gaba nan da nan ya kamata ya zama gwajin amincin ƙwaƙƙwaran (HTOL, ESD) da haɗawa cikin samfurin micro-display na monochrome don kimanta daidaiton pixel da crosstalk. Ga masu bincike, hanya a bayyane take: 1) Yi cikakkun nazarin electroluminescence a ƙarƙashin aikin bugun jini don warware tasirin zafi. 2) Yi amfani da kwaikwayon lokaci-bambance-bambancen iyaka (FDTD) don taswirar daidai yanayin gani a cikin waɗannan cavities na porous polygonal. 3) Bincika haɗin gwiwar wannan layer na porous tare da wasu dabaru, kamar haɗin plasmon na saman ko canza launin perovskite, don pixels na cikakken launi mai inganci sosai. Yin watsi da tambayoyin lantarki da amincin zai zama kuskure mai mahimmanci a fassarar kasuwanci.
7. Ayyukan Gaba & Hanyoyin Ci Gaba
- Micro-Displays Masu Ƙarfin Hasken Walƙiya: Don gilashin AR da nuni na kusa da ido inda girman pixel ya yi ƙanana kuma buƙatar haske ta yi tsanani.
- Nuni Kai Tsaye na LED Mai Ƙarfin Ƙuduri: Ba da damar ƙananan pixels masu inganci don bangon LED mai laushi da talabijin na masu amfani.
- Sadarwar Hasken Gani (VLC): Ƙunƙarar layi da haɓaka ƙarfin zai iya inganta ma'aunin sigina-zuwa-amo da ƙimar watsa bayanai.
- Haɗin Gani akan-Chip: Micro-LEDs azaman tushen haske mai inganci don photonics na silicon.
- Bincike na Gaba: Tsawaita dabarar zuwa Micro-LEDs na shuɗi da ja, haɗa ƙirar porous na musamman na tsawon zango don raka'a masu cikakken launi, da bincika crystals na photonic na porous 3D don sarrafa haske na ƙarshe.
8. Nassoshi
- Nakamura, S., et al. "The Blue Laser Diode: The Complete Story." Springer, 2000.
- Day, J., et al. "Full-Scale Self-Emissive Micro-LED Displays." Journal of the SID, 2019.
- Lin, J. Y., et al. "Micro-LED Technology and Applications." Nature Photonics, 2023.
- Li, C., et al. "GaN-based RCLED with nanoporous GaN/n-GaN DBR." Optics Express, 2020.
- Schubert, E. F. "Light-Emitting Diodes." Cambridge University Press, 2006. (Don ka'idar tasirin Purcell).
- International Roadmap for Devices and Systems (IRDS) - More Moore & Beyond CMOS, 2022 Edition. IEEE.
- Rahotannin bincike akan Micro-LED daga Yole Développement da DSCC.