白光发光二极管用CaAl_2B_2O_7_Eu_3_微晶的发光性质_英文_

白光发光二极管用CaAl_2B_2O_7_Eu_3_微晶的发光性质_英文_ 第 36卷 第 5期 人 工 晶 体 学 报 Vo .l 36 No. 5 2007 年 10月JOURNAL O F SYN TH ET IC CR YSTAL S O c tobe r, 2007 3 + L um inescen t Proper t ie s of CaA lBO: Eu 2 2 7 Crysta ll ite for W h ite L ight2em itt ing D iode 1 2 1 1 1 1YAN G Z h i2ping, T IAN J ing, L I X u, YAN G Guang 2w ei, W AN G S hao2li, L I Pan 2la i ( 1. Co llege of Physic s Sc ience and Techno logy, H ebe i U n ive rsity, B aod ing 071002 , Ch ina; )2. Co llege of E lec tron ic and Info rm ationa l Enginee ring, H ebe i U n ive rsity, B aod ing 071002 , Ch ina ( )R eceived 12 J une 2007 3 + A b stra c t: The CaA lBO: Eu c rysta llite wa s syn the sized by the h igh temp e ra tu re so lid sta te reac tion. 2 2 7 X2ray d iffrac tion p a tte rn show s tha t p u re CaA lBOm a trix wa s ob ta ined. The samp le can em it red ligh t 2 2 7 () unde r nea r2u ltravio le t UV and b lue L igh t exc ita tion. The em ission sp ec trum show s the mo st in ten se 5 7 3 + p eak is loca ted a t 614 nm , wh ich co rre spond s to the D ?F tran sition of Eu. The c rysta llite ha s two0 2 m a in exc ita tion p eak s loca ted a t 401 nm and 471 nm , wh ich m a tch the em ission of UV and b lue ligh t2 3 + () em itting d iode L ED re sp ec tive ly. The effec ts of cha rge comp en sa tion s and the concen tra tion of Euon + + + the em ission in ten sity we re a lso inve stiga ted. The co2dop ed K, N a and L ican a ll lead to the strongly 3 + + enhanced lum ine scence of CaA lBO: Eu . The samp le dop ed by L i ha s the h ighe st em ission 2 2 7 3 + 3 + in ten sity. The op tim um concen tra tion of Euis 6 %. The CaA l B O : Euc rysta llite is a po ten tia l red2 2 2 7 em itting p ho sp ho r fo r wh ite ligh t2em itting d iode. 3 + Key word s: L ED; c rysta llite; Eu; CaA l B O 2 2 7 ( ) CL C n um ber:O482 D ocum en t code:A A r t ic le ID : 10002985X 2007 0521178 204 3 + 白光发光二极管用 CaA lBO: Eu 微晶的发光性质 2 2 7 1 2 1 1 1 1杨志平 , 田 晶 , 李 旭 , 杨广伟 , 王少丽 , 李盼来 ( )1. 河北大学物理科学与技术学院 ; 2. 河北大学电子信息学院 , 保定 071002 3 + 摘要 :利用高温固相法合成了 CaA lBO: Eu 微晶 。X射线衍射分析明我们得到了纯相的 CaA lBO基质 。样 2 2 7 2 2 7 3 + 5 7 品在近紫外光和蓝光激发下能发出红光 。发射光谱的主峰位于 614 nm ,对应于 Eu的 D ?F 跃迁 。激发光谱中0 2 3 + 两个主峰位于 401 nm 和 471nm , 分别与紫外和蓝光 L ED 相匹配 。并研究了电荷补偿剂和 Eu的浓度对样品发光+ + + ()强度的影响 。所有掺入电荷补偿剂 L i, N a 和 K样品的发光强度都比没有掺入电荷补偿剂的样品高 。其中掺 + 3 + 3 + 入 L i的样品的发光强度最高 。 Eu的最佳浓度为 6 % 。CaA l B O : Eu是一种有应用前景的白光 L ED 用红色荧2 2 7 光粉 。 3 + 关键词 : L ED;微晶 ; Eu; CaA l B O2 2 7 1 In troduc tion () W h ite ligh t2em itting d iode L ED ha s advan tage s of low ene rgy con sump tion, long life tim e, lack of po llu tan ts Rece ived da te: 2007 206 212 ( ) B iogra phy: YAN G Zh i2p ing 1957 2, M a le, from H ebe i p rovince, P rofe sso r. E2m ail: yangzh ip ing786 @ sohu. com [ 1 , 2 ] such a s H g. R ecen tly, they have a ttrac ted mo re a tten tion becau se they a re stepp ing in gene ra l illum ina tion. It is we ll2known tha t the re a re ba sica lly two app roache s to gene ra te wh ite ligh t from L ED. O ne is to m ix ligh t of ()d iffe ren t co lo rs em itted by seve ra l ch ip s, and the o the r is to conve rt the em ission from a b lue o r u ltravio le t UV L ED to a longe r wave length ligh t u sing p ho sp ho rs. R e sea rche s on the la tte r have a ttrac ted mo re a tten tion and the p ho sp ho rs a re c ruc ia l in th is m echan ism. The re a re m any repo rts abou t the p ho sp ho rs app lied to the b lue o r UV [ 3 - 7 ] L ED . Up to now the mo st conven ien t way to gene ra te wh ite ligh t from L ED is u sing a b lue L ED and a ye llow 2em itting 3 + ( ) p ho sp ho r wh ich u sua lly m ade of ce rium dop ed yttrium a lum inum ga rne t YA G: Ce. B u t th is wh ite L ED 3 + fab rica ted w ith YA G: Cecanno t c rea te wa rm wh ite ligh t due to lack of red ligh t componen t. Th is p rob lem can be 3 + so lved by two ways: one is to comp en sa te the red defic iency of YA G: Ce2ba sed L ED w ith a sep a ra te red p ho sp ho r ( ) and the o the r is to com b ine an UV ch ip w ith trico lo r red, green and b lue p ho sp ho rs. In th is le tte r, the 3 + CaA lBO: Eu red2em itting c rysta llite wa s syn the sized and its lum ine scen t p rop e rtie s we re a lso inve stiga ted. 2 2 7 2 Exp e rim en ta l 3 + 2. 1 Prepa ra t ion of CaA lBO: Eu cry sta ll ite 2 2 7 3 + The CaA lBO: Eu samp le wa s p rep a red w ith a so lid sta te reac tion a t h igh temp e ra tu re. The sta rting 2 2 7 m a te ria ls u sed in the p rep a ra tion of th is c rysta llite we re p u re powde rs grea te r than 99. 9 % of CaCO, HBO, 3 3 3 A lOand EuO. The ind ividua l m a te ria ls we re we igh ted a t the app rop ria te sto ich iom e tric ra tio and m ixed 2 3 2 3 3 + suffic ien tly, then the powde r wa s ca lc ined a t 900 ? fo r 2. 5 h. The ob ta ined p roduc t wa s CaA lBO: Eu 2 2 7 c rysta llite. 2. 2 M ea surem en t procedure ( ) ( The p ha se of a s2p rep a red samp le s we re cha rac te rized by powde r X2ray d iffrac tion XRD D /m ax - rA , α2540 u ltravio le t ) The exc ita tion sp ec trum wa s m ea su red by a SH IMAD ZU R FCuK, 40 kV , 100mA . sp ec trop ho tom e te r. The em ission sp ec trum wa s m ea su red by a SPEX1404 sp ec trop ho tom e te r. A ll the p ho to lum ine scence p rop e rtie s we re ob ta ined a t room temp e ra tu re. 3 R e su lts and d iscu ssion 3 + F ig. 1 show s the XRD p a tte rn of CaA lBO: Eu . It agree s we ll w ith Jo in t Comm ittee on Powde r D iffrac tion 2 2 7 3 +() Standa rd s JCPD S No. 1920206ind ica ting tha t the dop ed Eu ha s no t cau sed any sign ifican t change in the ho st struc tu re. CaA lBOha s a monoc lin ic c rysta l struc tu re 2 2 7 and the la ttice p a ram e te rs a re a = 0. 418 nm , b = 1. 559 nm , c = 0. 816 nm. 3 + The exc ita tion sp ec trum of CaA lBO: Eu 2 2 7 c rysta llite is dep ic ted in F ig. 2. The b road exc ita tion band 3 + 2 + Eu2O2 cha rgeto the befo re 350 nm is a ttribu tab le ( )tran sfe r C2T tran sition, and the sha rp line s in 350 2 500 nm range co rre spond to the cha rac te ristic f2f 3 + Eutran sition s of in the ho st la ttice s. The re a re two 7 5 7 ) (( dom ina tive p eak s a t 401 nm F ?L and 471 nm F 0 6 0 3 + Fig. 1 XRD pa ttern of Eudoped CaA l B O 5 2 2 7 )?D , wh ich m a tch we ll w ith the UV and B lue L ED 2 3 + ( ) ( ( ) )aCaA lBO: Eu ; bCaA lBOJCPD S No. 1920206 2 2 7 2 2 7 ch ip s re sp ec tive ly. 36卷 第 1180 人 工 晶 体 学 报 3 + The em ission sp ec trum of CaA lBO: Eu c rysta llite is p re sen ted in F ig. 3. It is found to exh ib it a red 2 2 7 5 7 em ission unde r exc ita tion of 401 nm. The stronge st em ission p eak wa s ob se rved a t 471 nm due to D ?F e lec tric0 2 5 7 7 7 d ipo le tran sition, and o the r em ission p eak s we re a sc ribed to the tran sition D leve l to F , F and F leve ls of 0 1 3 4 3 + 3 + Eu, re sp ec tive ly. The re su lt ind ica te s tha t mo st Eua re loca ted a t site s w ithou t inve rsion symm e try. 3 + λ()F ig. 2 The exc ita tion sp ec tra of CaA lBO: Eu = 614nm 2 2 7 em 3 + F ig. 3 The em ission sp ec tra of CaA lBO: Fig. 4 The dep endence of the Euconcentra tion 2 2 7 3 +3 + (λ xEu ) on the em ission inten sity of CaA l B O : Eu= 401nm 2 2 7 ex 3 + 3 + Euthe em ission in ten sity of CaA l B O : Euc rysta llite wa s a lso The effec t of dop ed concen tra tion on 2 2 7 3 + ( ) inve stiga ted. A se rie s of samp le s CaA lBO: x Eu x = 4 % , 5 % , 6 % , 7 % , 8 % sp ec im en s we re p rep a red. 1 2x 2 2 7 3 + U nde r exc ita tion of 401 nm , the 614 nm em ission in ten sitie s of samp le s w ith d iffe ren t Euconcen tra tion a re shown 3 + in F ig. 4. The em ission in ten sity inc rea se s w ith Eucon ten t inc rea sing un til a m axim um in ten sity is reached, and then it dec rea se s becau se of concen tra tion quench ing. The m axim um in ten sity occu rs when the concen tra tion of 3 + is 6 %. Eu3 + 3 + 3 + W hen Euis in low concen tra tion, the in te rac tion of Eu2Euis ve ry lim ited. The in ten sitie s of em ission and 3 + 3 + exc ita tion inc rea se w ith the inc rea se of the Euconcen tra tion, and reach m axim um. If the concen tra tion of Eu3 + 3 + con tinue s to inc rea se, the in te rac tion of Eu2Euinc rea se s, wh ich lead s to concen tra tion quench, so the em ission in ten sity becom e s lowe r. 3 + 3 + 2 + In the CaA lBO: Eu c rysta llite, Eu is exp ec ted to rep lace Ca . It wou ld be d ifficu lt to keep cha rge 2 2 7 3 + 2 + ba lance in the c rysta llite samp le, so Eum ay no t be fu lly in troduced in to Casite. Con sequen tly, we add un iva len t + + + [ 8210 ] ( ) cha rge comp en sa tion K, N a and L iin o rde r to keep cha rge ba lance. A se rie s of samp le s Ca M 0. 88 0. 06 3 + + + + 3 + ( ) 0 6 Eu sp ec im en swe re p rep a red. The ir A lBO: 0. 06Eu M = K , N a and L i and CaA lBO: 0. 2 2 7 0. 94 2 2 7 + + + em ission sp ec tra, unde r exc ita tion of 401nm , a re shown in F ig. 5. The co - dop ed K, N a and L ican a ll lead to 3 + 3 + the strongly enhanced lum ine scence of CaA lBO: Eu . The samp le CaL iA lBO: 0. 06Eu ha s the h ighe st 2 2 7 0. 88 0. 06 2 2 7 + + + + em ission in ten sity. The rad iu s of K, N a and L ia re 0. 133nm , 0. 097nm and 0. 059nm re sp ec tive ly. Since L iha s 3 + the lea st rad iu s, it can be dop ed in m a trix mo st ea sily and he lp Euen te r ho st m a te ria l mo st effec tive ly. The refo re, + 3 + the samp le co2dop ed by L iand Euha s the stronge st em ission. 4 Conc lu sion s 3 + In the p re sen t wo rk, the CaA lBO: Eu c rysta llite ha s been syn the sized by conven tiona l h igh temp e ra tu re 2 2 7 ( ) so lid sta te m e thod. The samp le can em it red ligh t unde r nea r2u ltravio le t UV and b lue ligh t exc ita tion. The + + + ( ) in troduc tion of cha rge comp en sa tion s K, N a and L ican a ll lead to the strongly enhanced lum ine scence of 3 + 3 + EuL i A l B O : 0. 06 Euha s the h ighe st em ission in ten sity. CaA l B O : in CaA l B O . The samp le Ca 2 2 7 0. 88 0. 06 2 2 7 2 2 7 3 + Euc rysta llite is a po ten tia l p ho sp ho r fo r UV and b lue L ED due to two strong exc ita tion p eak s a t 401 nm and 471 nm re sp ec tive ly. Referen ce s [ 1 ] Zhong J , Chen H , Saraf G, e t al. In tegra ted ZnO N ano tip s on GaN L igh t Em itting D iode s fo r Enhanced Em ission Efficiency [ J ]. A ppl. Phys. L ett. , 2007 , 90: 203515. [ 2 ] Yang Ch ih2ch ieh, L in Ch ih2m in , Chen Yi2jung , e t a l. H igh ly Stab le Th ree2band W h ite L igh t from an InGaN 2ba sed B lue L igh t2em itting D iode () Ch ip P recoa ted w ith O xyN itride Green / red Pho sp ho rs[ J ]. A ppl. Phys. L ett. , 2007 , 90: 123503. X ie Rong2jun , N ao to H iro sak i, N aok i Kim u ra, e t a l. 2 2p ho sp ho r2converted W h ite L igh t2em itting D iode s u sing O xyn itride / n itride Pho sp ho rs[ J ]. [ 3 ] A ppl. Phys. L ett. , 2007 , 90: 191101. Joung Kyu Park, Kyoung Jae Cho i, H yun Goo Kang, et a l. Silica te Pho sp ho rs fo r W h ite L ED s Iden tified th rough Com b inato ria l Chem istry [ J ]. [ 4 ] E lectrochem. S olid 2S ta te L ett. , 2007 , 10: J15. N aok i Kim u ra, Ken Sakum a, Syun ich iro H irafune, e t a l. Extrah igh Co lo r R ende ring W h ite L igh t2em itting D iode L amp s U sing O xyn itride and [ 5 ] N itride Pho sp ho rs Exc ited by B lue L igh t2em itting D iode [ J ]. A ppl. Phys. L ett. , 2007 , 90: 051109. 3 + + [ 6 ] Ho Seong Jang, D uk Young Jeon. Ye llow2em itting SrSiO: Ce, L i Pho sp ho r fo r W h ite2ligh t2em itting D iode s and Yellow 2ligh t2em itting D iode s 3 5 [ J ]. A ppl. Phys. L ett. , 2007 , 90: 041906. 3 +Ya suo Sh imom u ra, Te tsuo Honm a, Mo toyuk i Sh ige iwa, et a l. Pho to lum ine scence and C rysta l Structu re of Green2em itting CaScSiO: Ce [ 7 ] 3 2 3 12 Pho sp ho r fo r W h ite L igh t Em itting D iode s[ J ]. J. E lectrochem. S oc. , 2007 , 154 , J35. Th iyaga ra jan P, Ko ttaisam y M , R am achand ra R ao M S. Low Temp e ra tu re Syn the sis of SrS: Ce Pho sp ho r by Ca rbo the rm a l R educ tion M e thod: [ 8 ] Influence of Su lfu r and Cha rge Comp en sa to r on the L um ine scen t P rop e rties[ J ]. M a teria ls R esea rch B u lletin , 2007 , 42: 753 2761. 3 + [ 9 ] ( ) Sahoo R , B ha ttacha rya S K, D ebna th R. A N ew Typ e of Charge Comp en sating M echan ism in CaPOF: EuPho sp ho r[ J ]. J ou rna l of S olid 5 4 3 S ta te C hem istry, 2003 , 175: 218 2225. 3 + [ 10 ] W ang Zhengliang , L iang Hongb in, Gong M englian , e t al. L um inescence Investiga tion of EuA c tivated Doub le Mo lybda te s R ed Pho sp ho rs w ith Schee lite Structu re [ J ]. J ou rna l of A lloys and Com pounds, 2007 , 432: 308 2312.