Wannan binciken ya gabatar da wani sabon nau'in kayan haske: nanoparticles na tsarin imidazolate na zeolite-8 da ke ɗauke da fluorescein (fluorescein@ZIF-8). Aikin ya magance wata ƙalubale mai mahimmanci a cikin haske mai tsayayye (SSL)—ƙirƙirar ma'adanai masu haske (phosphors) masu inganci, masu daidaitawa, kuma marasa sinadarin ƙasa da ba a cika samunsu ba (REE-free) don fitilun LED na farin haske (WLEDs). Ta hanyar amfani da kaddarorin tsare-tsare a cikin nano (nanoconfinement) na Tsarukan Ƙarfe-Organic (MOFs), binciken ya yi nasarar rage kashe haske da taruwa ke haifarwa (ACQ) na rini na organic fluorescein, inda ya sami babban yawan samar da haske mai tsayayye (QY) har zuwa kusan ~98%.
An ƙirƙiri nanoparticles ta hanyar kira guda ɗaya (one-pot synthesis) inda aka haɗa zinc nitrate hexahydrate da 2-methylimidazole a cikin methanol tare da bambancin yawan gishirin sodium na fluorescein. Wannan hanyar tana ba da damar ɗaukar baƙo mai iya aunawa da sarrafawa a cikin matrix ɗin mai masaukin ZIF-8 mai ramuka.
An yi amfani da tsarin tantancewa mai fuskoki da yawa:
PXRD ta tabbatar da kiyaye tsarin crystalline na ZIF-8 bayan ɗaukar ciki. FTIR da simintin ka'idar sun ba da shaida ga nasarar shigar da fluorescein a cikin kejin, musamman ta hanyar raunin hulɗa (misali, van der Waals, taruwar π-π) maimakon haɗin covalent, wanda ya hana zubar da rini.
Tazarar rukuni (band gap) na haɗaɗɗen abu ya yi daidai da ƙimar da aka lissafta ta DFT. Binciken tsawon rayuwar haske ya bambanta tsakanin monomers masu keɓancewa da nau'ikan taruwar fluorescein. Mafi mahimmanci, a ƙananan yawan rini, yawan samar da haske (QY) ya kusanci kusan haɗin kai (~98%), wani babban nasara ne ga mai fitar da haske na organic mai tsayayye, wanda aka danganta kai tsaye ga hana ACQ ta hanyar mai masaukin MOF.
Nanoparticles na fluorescein@ZIF-8 sun nuna ƙarfafa kwanciyar hankali na haske sosai idan aka kwatanta da fluorescein kyauta. Tsarin ZIF-8 mai ƙarfi yana aiki azaman garkuwa mai kariya, yana keɓance ƙwayoyin rini da rage hanyoyin lalata haske (photobleaching), wata gagarumin nakasa ta rini na organic.
An ƙirƙiri WLED na tabbatar da ra'ayi ta hanyar lulluɓe ɗan ƙaramin guntun LED na shuɗi (λem ~450 nm) da ɗan bakin fim na nanoparticles na fluorescein@ZIF-8. Ta hanyar daidaita yawan fluorescein da kauri na fim, na'urar ta fitar da haske mai launuka da yawa masu daidaitawa, gami da farin haske mai dumi tare da daidaita madaidaitan Hukumar Haske ta Duniya (CIE) a cikin wani yanki mai dacewa.
~98%
Don fluorescein@ZIF-8 mai ƙananan yawa
Mahimmanci
Saboda tsare-tsaren ZIF-8 a cikin nano (nanoconfinement)
Farin Haske Mai Daidaitawa
An nuna ta hanyar na'urar MOF-LED
LG@MOF
Baƙo mai haske a cikin Tsarin Ƙarfe-Organic (Luminescent Guest@Metal-Organic Framework)
Mahimman Fahimta: Mai masaukin MOF ba wai kawai yana aiki azaman akwati mara aiki ba amma yana ƙera yanayin haske na baƙon a zahiri, yana canza kaddarar yanayin magani (babban QY) zuwa aiki mai ƙarfi na tsayayye.
Ingancin Canja Wutar Makamashi ta Förster Resonance (FRET), wanda zai iya haifar da kashe haske a cikin rini da aka tattara, yana ƙarƙashin lissafin:
$E = \frac{1}{1 + (\frac{r}{R_0})^6}$
inda $E$ shine ingancin FRET, $r$ shine nisa tsakanin ƙwayoyin mai bayarwa da mai karɓa, kuma $R_0$ shine radius ɗin Förster. Tsarin ZIF-8 yana raba ƙwayoyin fluorescein ta sarari, yana ƙara $r$ da rage $E$ sosai, don haka yana hana kashe haske da yawa. Bayanan tsawon rayuwar gwaji ($\tau$) na monomers da taruwa sun dace da ƙira don nau'ikan da ba sa hulɗa ($I(t) = A_1 e^{-t/\tau_1}$) da nau'ikan masu hulɗa ($I(t) = A_1 e^{-t/\tau_1} + A_2 e^{-t/\tau_2}$), bi da bi.
Hoto na 1 (Hasashe bisa abubuwan ciki): Taswira mai kwance (bar chart) tana kwatanta Yawan Samar da Haske na Photoluminescence (PLQY) na foda na fluorescein kyauta, fluorescein a cikin magani, da fluorescein@ZIF-8 a ƙananan/babban ɗauka. Sandar fluorescein@ZIF-8 (ƙananan ɗauka) za ta fi sauran girma, tana nuna yawan samar da ~98% a zahiri.
Hoto na 2: Taswirar launi ta CIE 1931. Jerin maki zai nuna launukan fitar da haske masu daidaitawa da za a iya samu daga na'urar MOF-LED ta hanyar bambanta yawan fluorescein. Tarin maki kusa da ma'anar farin haske (0.33, 0.33) zai wakilci nasarar samar da farin haske.
Hoto na 3: Taswira ta ƙarfin PL da aka daidaita da lokacin haskakawa. Lankwalin fluorescein@ZIF-8 zai nuna raguwa a hankali, yayin da lankwalin fluorescein kyauta zai faɗi da sauri, yana nuna ƙarfafa kwanciyar hankali na haske.
Tsarin Kimanta Ma'adanai Masu Haske na LG@MOF:
Nazarin Lamari - Wannan Takarda: Marubutan sun yi amfani da wannan tsarin daidai. An zaɓi ZIF-8 saboda kwanciyar hankalinsa da ramuka masu dacewa. Girman da fitar da haske na Fluorescein sun dace. Kira ya haifar da ɗaukar kaya mai sarrafawa. Ma'auni na ƙarshe (98% QY, madaidaitan CIE, ingantaccen kwanciyar hankali) sun tabbatar da hanyar.
Mahimman Fahimta: Wannan ba wani takarda na MOF kawai bane; darasi ne a cikin ƙera kaddarori ta hanyar tsare-tsare a cikin nano (nanoconfinement). Marubutan ba kawai sun yi sabon kayan aiki ba; sun warware matsala ta asali ta ilimin haske—kashe haske mai tsayayye—ta hanyar amfani da MOF a matsayin "dakin gwaje-gwaje na nano" mai daidaito don keɓance ƙwayoyin rini. Kusan haɗin kai na QY sakamako ne mai ban mamaki wanda ya kamata masu kera ma'adanai masu haske na gargajiya su lura.
Kwararar Hankali: Hankali yana da kyau: 1) Gano ACC a matsayin makullin ma'adanai masu haske na organic SSL. 2) Hasashen cewa ramukan MOF na iya hana taruwa. 3) Kira da tabbatar da ɗaukar ciki. 4) Auna QY mai tsayayye da ba a taɓa gani ba. 5) Nuna na'ura mai aiki, mai daidaitawa. 6) Danganta nasara ga tsare-tsare a cikin nano ta hanyar binciken tsawon rayuwa. Cikakken sarkar daraja ne daga hasashe zuwa aikace-aikace.
Ƙarfi & Kurakurai: Ƙarfinsa shine babban QY mai ban sha'awa da na'urar tabbatar da ra'ayi mai kyau. Hanyar haɗa gwaji da ka'idar tana da ƙarfi. Duk da haka, kurakurai—gama gari a cikin binciken kayan aiki na ci gaba—shine tazarar tsakanin abin al'ajabi na sikelin dakin gwaje-gwaje da samfurin kasuwanci. Takardar ta ambaci "mai iya aunawa" amma ba ta nuna kira na sikelin kilogiram ba. Kwanciyar hankali na zafi da ɗanɗano na dogon lokaci na fim ɗin MOF akan guntun LED mai zafi (>100°C) ba a bincika ba. Kamar yadda aka lura a cikin bita akan Nature Reviews Materials, canji daga ilimin haske na dakin gwaje-gwaje zuwa amincin na'ura shine babban cikas ga na'urorin gani na tushen MOF.
Fahimta Mai Aiki: Ga masu bincike: Mayar da hankali gaba kan sarrafa fim—lulluɓe da jujjuyawa, buga waɗannan nanoparticles ta hanyar buga tawada don yadudduka masu daidaitu, masu mannewa. Bincika sauran haɗuwar rini@MOF (misali, mai fitar da ja) don cikakken bakan LED na farin haske. Ga masana'antu: Wannan fasahar wata fa'ida ce mai ban sha'awa, madadin REE-free. Haɗin gwiwa tare da dakunan gwaje-gwaje na ilimi don gwada tsawon rayuwar na'ura da haɓaka ƙa'idodin masana'antu masu tsada, masu inganci. Shirin SSL na Ma'aikatar Makamashi ta Amurka ta jaddada buƙatar sabbin kayan aiki masu inganci; wannan aikin ya dace da buƙatar daidai.
A ƙarshe, wannan binciken yana ba da zane mai ƙarfi. Kamar yadda takardar CycleGAN mai mahimmanci (Zhu et al., 2017) ta nuna yadda ake koyon fassarar hoto zuwa hoto ba tare da bayanan haɗin gwiwa ba, wannan takarda tana nuna yadda ake fassara kaddarar gani na yanayin magani zuwa yanayin tsayayye ba tare da asara ba—ta amfani da ƙirar kayan aiki mai wayo. Nan gaba na haske bazai zama inorganic ko organic kawai ba, amma haɗaɗɗen abu inda MOFs ke taka muhimmiyar rawa a matsayin injiniyan gani na ma'aunin ƙwayoyin cuta.