Nghiên cứu các tính chất quang của hợp chất bán dẫn vùng cấm rộng

DAI HOC QUOC GIA HA NOI TRITOING DAI HOC KHOA HOC TlT NHIEN DE TAI: NGHIEN ctru CAC TINH CHAT QUANG CUA HOP CHA BAN DAN VUNG CAM RONG Ma so: QT- 05-08 Chi4 tri de rai : Cdc cdn bg tham gia : TS Pham Van Ben ThS Hoang Chi Hieu CN Nguyen Thanh Chuong CN Nguyen Anh Tuan rJAi HOC Q U O C GIA HA NOI rpuMG TAW THONG TIN THU ViEN or I b^^ HA NOI - 2005 BAO CAO TOM TAT ^•^ DETAI: NGHIEN CUtJ CAC TINH CHAT QUANG CUA HOP CHAT BAN D A N VUNG CAM RONG MA SO : QT- 05 - 08 CHU TRI DE TAI : TS PHAM VAN BEN CAC CAN B O THAM GIA: TH.S HOANG CHI HIEU CN NGUYfiN THANH CHUONG CN NGUYfiN ANH TUAN Muc tieu va noi dung nghien curu: + Xay dung he kfch thich va thu huynh quang tren ca so may sdc each tu kep GDM - 1000 va ky thuat lock-in + Nghien cuu cac tfnh chat quang cua cac hop chat ban dSn viing cam i Cac ket qua dat dupe + Tim hieu ly thuyet vl tfnh chat quang cua cac hgp chat ban dSn vimg cam rong + Xay dung he kfch thfch va thu huynh quang tren ca so may dc sdc each tir kep GDM - 1000 va ky thuat lock- in + Thu va nghien ciJu huynh quang cua cac hop chat ban dSn vian cam rong ZnSe, ZnS \'a ZnS : Mn '^' Kei qud dao tao: 03 sinh vien bac cu nhan * Cdc cong trinh cong bo: 02 bao cao khoa hoc tai Hoi nghi Vat ' toan quoc lan thu \a Ha Noi tir 23 - 25/11/2005 Tinh hinh sur dung kinh phi + Tong kinh phi duoc cap 20.000.000d + Tien dien, nude va xSy dung co scf vat chat SOO.OOOd + v a t tu van phong SOO.OOOd 2.000.000d + Hoi nghi, in an bao cao : l.OOO.OOOd + Cong tac phi, tau xe S.OOO.OOOd + Thue mucfn + Chi phi nghiep vu chuyen mon : V.OOO.OOOd + Ho tro dao tao nghien ciiu khoa hoc : 400.000d XAC NHAN CUA BCN KHOA VAT LY PGS.TS Nguy in The Binh CHU TRI DE TAI TS Pham Van Ben PHO HlEl TRUOHG GS.TS.'^i**^ ^JC BRIEF REPORT TTTLE: INVESTIGATION ON THE OPTICAL PROPERTIES OF SEMOCONDUCTOR COMPOUNDS WITH THE WIDE BAND GAP CODE: QT- 05-08 COORDIMATOR : PHAM VAN BEN KEY IMPLEMENTS: HOANG CHI HIEU NGUYEN THANH CHUONG NGUYEN ANH TUAN Objective and Matter of this study: + To construct the excitation system and obtain luminescence spectra using the double grating spectrometer GDM 1000 and the lock-in amplification technique + To investigate the optical properties of semiconductor compounds with the wide band gap Main results: We succeeded in: + Carrying out the theory of optical properties of wide-band gap semiconductors + Constructing excitation system and obtain luminescence spectra using the double grating spectrometer GDM -1000 and the lock-in amplification technique + Investigating some optical properties of some wideband gap semiconductor compounds such as ZnSe, ZnS and ZnS:Mn Education results: bachelor theses Publications: papers on Tlie 6^^ Vietnamese Confference on Physic, Hanoi November 23-25, 2005 MUC LUC 1, Md dau H Noi dung i Cdc tinh chdt quang cua cdc hgp chat bdn ddn vung cdm rpng a Cau tnic tinh the va cau tnic vung nang lugng b Su thay doi rong viing cam theo nhiet c Su thay doi rong vung cam theo nong tap chat d Cac ca che hap thu ban din vung cam rong e Cac ccf che tai hgp biic xa ban dSn vung c^m rong 2, Xdy dung he kich thich vd thu phd huynh quang, tdn xa Raman tren ca sd mdy dcm sdc cdch tu kep GDM -1000 diing ky thuat lock - in a Md dau b He kfch thfch huynh quang va tan xa Raman c He thu huynh quang va tan xa Raman d Cac ket qua huynh quang va tan xa Raman e Ket luan 3, Nghien citu tinh chdt quang cua bdn ddn viing cdm rong ZnSe a Ma dau b MSu nghien ciJu va thiet bi thuc nghiem c Cac ket qua va bien luan ^ Pho phat quang (huynh quang) ciia tinh the ZnSe * Su phu thuoc vi trf va cucmg ciia dam phat quang \aing da cam-do a 606 nm vao mat nang lugng kfch thfch * Su t^t nhiet phat quang cua tinh the' ZnSe d Ket luan 4, Pho huynh quang cua bdn ddn vung cdm rong ZnS vd ZnS : Mn 5, Kit ludn 6, Tdi lieu tham khao 7, Phu luc - 02 bdi bdo tai hoi nghi vat ly toan qudc Idn thit nam 2005 ' 03 khod ludn tdt nghiep nam 20.04-2005 L MO DAU Cac hgp chat ban din vung cam rong loai A^B^ A^B^ v6i rong vung cam khoang mot vai electron von nhu: ZnSe, ZnS, CdTe, CdS, ZnO.vv dugc ling dung rong rai cac dung cu quang dien tu Chiing dung de che tao cac di ot phat quang, quang tra, nhung cua so suot viing kha kien va hong ngoai gin [1, 2, 3, 4] Trong ph6 phat quang cua cac hgp chat ban din tii 4,2K den 300K, ngoai nhiing vach dac trung cho su tai hgp biic xa cua cac exciton tu do, exciton lien ket tren cac donor, acceptor, cac electron tu tir viing din xuong cac miic tap chat, xu^'t hien cac dam rong dac trung cho su tai hgp biic xa cua cac cap donor - acceptor [5, 6, 7, 8, 9] Khi pha cac kim loai chuyen tiep nhu Mn, Fe, Ni, Co vdi vo dien tir 3d chua lap day vao cac hgp chat ban din wng c^'m rong se tao cac ban din ban tir Cac ion ciia cac kim loai tren (goi la cac ion tijf) se tao nen viing cam ciia cac hgp chat ban din nhiing miic nang lugng xac dinh Vl the phat quang ciia cac hgp chat ban din vung cam rong xuat hien nhiing \'ach dac tnmg cho su tai hgp biic xa cua cac polaron tii lien ket, cac dam phat quang dac tnmg cho cac ion tii va phat quang cua chiing dugc chuydn sang viing hong ngoai gan [10, 11, 12, 13, 14] Nhim lam sang to mot vai ca che tai hgp biic xa va kha nang iing dung ciia cac hgp chat ban din viing cam rong, chiing toi thuc hien de tai: Nghien ciiu cac tfnh chat quang cua hgp chat ban din \aing cam rong n NOI DUNG Cac tinh chat quang cua cac hgp chat ban dSn vung cam rong a Cau true tinh the va cau true viing nang lixgng * Cdu trdc tinh the Cac tinh thd A'B^ A^B' dugc tao tii cac kim tu nhom hoac (A) va cac nguyen tir a kim nhom hoac (B) lien ket vcd theo dang h6n hgp ion va cong hoa tri (vi du nhu ZnS :77% la lien ket ion va 23% la lien ket cong hoa tri) Trong hen ket ion cac nguyen tu kim loai A cho hai dien tir hoa tri de tra ion hoa tri duong hai A^"^ co c^'u hinh dien tii a Icfp ngoai ciing 3d^pM^°, cac nguyen tir a kim B nhan hai dien tir tra ion hoa tri am hai B^' CO cau hinh ldp dien tu ngoai ciing 3s^p^ Trong lien ket cong hoa tri m6i nguyen tir A hay B deu dong gop vao lien ket chung dien tii de tao cau hinh day dii ciia 16p vo dien tu Nguyen tu A se tra ion hoa tri am hai A^' CO cau hinh dien tu ngoai cung 4s^p^ nguyen tir B se tra ion hoa tri duong hai B^"" vdi cau hinh Icfp vo ngoai cung 3s^p^ Cac nguyen tii A va B lien ket v6i theo mot cau tnic tuan hoan, tao tinh thd Cd nhieu dang hinh thii khac ciia tinh the ban din viing cam rong, nhung deu xuat phat tir hai dang co ban: dd la cau tnic luc giac (Wurtzite) va cau tnic lap phuang (Sphalerite hay Zincblende) Vide tinh thd nhan cau tnic luc giac hoac lap phuang la thuoc vao nhiet va ban chat ciia tiing hgp chat ban din Vai tinh the ZnS thuoc nhdm A-^B^ thi a nhiet nung nho han 950°C tinh thd thudng cd cau tnic lap phuang a nhiet tir 950*^ den 1020^C thi cd khoang 70% ZnS a dang cau true luc giac va a nhiet tir 1020°C den 1200°C, ZnS hoan toan o dang cau tnic luc giac Nhu vay cd thd xem 1020^C la nhiet chuydn pha tir cau tnic lap phuang sang cau tnic luc giac V6i cac tinh thd thuoc nhdm A'B' thi mang tinh thd ciia chiing thudng cd cau tnic dang lap phuang Tuy nhien khong thd xac dinh dugc khoang nhiet 6n dinh cho timg dang ca'u hinh cua tinh the Vdi CdTe, cau tnic dang luc giac chi quan sat thay d mau mang cdn cau tnic dang lap phuang quan sat thay d miu rdn Du d dang cau tnic luc giac hay cau true lap phuong thi lidn kd't trat tu gan, mdi nguyen tir A^ (hay B^) ddu nim d tam ciia hinh tii dien tao bdi bdn nguyen tir B^ (hay A') * Cdu trdc dang lap phucmg (Sphalerite hay Zincblende) Cau tnic dang lap phuang dugc xay dung trdn co sd xdp quy luat xep ciu ciia hinh lap phuong vdi cac dinh la nguyen tir B (S) dugc ky hieu la O Cac nguyen tir A (Zn) nam mot nira sd hdng bdn mat, cac hdng A (Zn) dugc kyfcidu la dinh hudng song song vdi (hinh a) Hinh 1: Cau tnic cua ban din vung cam rong a : Dang lap phuang ( Sphalerite hay Zincblende ) b : Dang luc giac ( hay Wurtzite ) Nguydn tir A dugcky hieu la : ^ Nguydn tir B dugc ky hieu la: O Nhdm ddi xiing khong gian cua Sphalerite la: T"^ F43m cau tnic Sphalerite, mdi mang ngu\en td cd phan tir A^B^ (ZnS) Mdi nguyen tir A (Zn) dugc bao quanh bdi nguydn tir B (S) dugc dat trdn cac dinh cua tii dien d cung khoang each ^ / - dd a la hing sd mang Ngoai bat ky mot nguyen td nao thuoc ciing mot loai cung dugc bao quanh bdi 12 nguyen tir ciing loai dd d khoang each V2-, dd nguyen tir dat d dinh cua luc giac nim trdn ciing mot mat phang, nguyen tii cdn lai tao mot phan lang kfnh tam giac Neu dat cac nguyen tir cua mot nguyen td B (S) d cac niit mang lap phuong, tam mang cd toa dg-cau la (0, 0, 0) thi cae nguydn tii cua nguydn td tai cac mit mang ciia tinh the Sphalerite nay, nhung vdi niit mang dau cd toa (1/4, 1/4, 1/4) Khi dd nguyen tir B (S) d cac vi tri (0, 0, 0); (1, 1/2, 1/2); (1/2, 0, 1/2); (1/2, 1/2, 0) va nguydn tir A (Zn) d cac vi tri (1/4, 1/4, 1/4); (1/4, 3/4, 3/4); (3/4, 1/4, 3/4); (3/4, 3/4, 1/4) [s] * Cdu true dang luc gidc (hay Wurtzite) + Cau tnic dang luc giac (hay Wurtzite) dugc xay dung dua tren co sd quy luat xep cau theo hinh canh cua cac nguydn tir B (S) dugc kyOidu la dd mot nira sd hdng bdn mat chiia nguydn tir A dugc ky hieu la # dinh hudng song song vdi ( hinh lb) Nhdm ddi xiing khong gian cua cau tnic luc giac la: (^^^ - P63wc O cau tnic Wurtzite, mdi mang nguydn td ciing chiia phan tir A^B"^ (ZnS) Toa cua mdi nguydn tir A dugc bao quanh bdi nguydn tir B (Z) dat tren cac dinh tii dien d ciing khoang each [aV3 + c^(u - 1/2)"]'^ , dd a la hing sd mang, u la hing sd mang doc theo true Z Ngoai bat ky mot nguydn td nao thuoc ciing mot loai cung dugc bao quanh bdi 12 nguyen tir cung loai dd, dd cd nguyen tir d dinh ciia mot luc giac nim cimg mat phing vdi nguydn tir dau va each nd mot khoang la a, nguydn tir d dinh mat lang tru cd day la mot tam dien d khoang each bang [^^ + —] J ~ Cac toa cua cac nguydn tir A (Zn) la (0, 0, 0); (1/3, 2/3, 1/2): va cac toa ciia cac nguyen tuB(S) la (0, 0, 4); (1/3 2/3, 1/2 + u) [3] NANG CAP HE MAY QUANG PHO CACH TLT KEP GDM-1000 PHUC VU NGHIEN c u t ! QUANG PHO HOC LASER (Tieu ban Quang hpc Quang pho) Nguyen The Binh, Pham Van Bin ^Nguyln Anh Tuin, Du-ong Vu Tru-oTig, Nguyln Thi H^ng Khoa Vat ly, Dai hoc KHTN, Dai hoc Qu6c gia Ha noi 334 dudng Nguyln trai, Thanh Xuan, Ha noi Tren ca sa may quang ph6 each tii kep GDM-1000 (Carl-Zeiss Jena) chung toi da nghien curu thay the ky thuat tir ghi bang ky thuat ghep n6i may tinh, su dung khuech dai Lock-in (DSP-Lock-in Amplifier SR 830) va thay nhan quang dien mdi (R-928 Hamamatsu) de nang cao 66 nhay va md rong vung lam viec Mot he thu ph6 Raman kich thich bang laser Argon va laser He-Ne da dugc xay dung cong cho phep nghien cuu cau true phan tu ciia cac phan dung dich huu ca, mot so thuoc tinh quang hoc cua cac mau vat lieu ban dan Viec thu Raman kich thich bang laser He-Ne da han che cd hieu qua anh hirdng cua cac dam huynh quang Raman cua cac phan dung dich huu co nhu la chiet pham dau md Ben canh phd Raman laser, he may quang cdn cho phep chung tdi nghien cuu phd huynh quang laser ciia nhieu vat lieu kliac nhau, nghien cuu cau true phd laser cung nhu quang phd hoc quang hoc phi tuyen I - MO DAU Xay dimg mot he quang c6 nhay tot, on dinh va nang suat phan giai cao la mong muon ctia nhieu phong thi nghiem quang Nhu chung ta da biet, cac phuang quang hoc laser bao gom quang hgc Raman, huynh quang hap thu da \'a dang dugc ung dung rong rai de nghien cuu cau true phan tu, hoa dau moi truong nuac va khi, thuoc tinh vat lieu quang dien tu ke ca vat lieu cau true nano Gan da>' cac hieu ung phi tu>'en phat tan so tong va phat hoa ba bac hai da trd cong cu quang de khao sat be mat vdi dac trung be mat cao [1] Quang hoa ba bac hai dugc biet den nhu mot txng cu vien noi bat nham hieu ro hon ve tinh chat quang ciia cac cSu tnic nano [2] Ngudi ta rat can cac he quang thu dugc tin hieu y^u, x§p xi nhilu on Nhung he may quang nhu vay noi chung rat dat tien Chung toi da nghien cuu nang cap he may quang GDM-1000 cua hang CarlZeiss Jena CHDC Due cu mot he thu quang su dung ky thuat khuech dai Lock-in co ghep ndi xu ly s6 lieu tren may tinh.May quang each tu kep GDM1000 CO nang suit phan giai cao nhung phan dien tu thuoc the he cij su dung tu ghi vdi nhan quang dien loai head-on M12FC vdi vung nhay phd 400-500nm He may nav thich hgp vdi viec thu phd Raman kich thich bang laser Argon cdng suat cd 35W lien tuc hoac den thuy ngan Tuy nhien thu phd bang tu ghi la mdt bat tien Idn khone cdn phu hgp.Chung tdi da thay the he thu phd tu ghi bang ghep ndi may tinh cuns^'ai su dung bg khulch dai Lock-in DSP-SR830.Stanford (USA) de tang nhay va dn dinh.lvlgt mota budc thich hgp dugc ghep vao de dieu kliien chinh xac soc'quay cua each tu He thu phd mai dugc dieu kliien \ a thu thap sd lieu thdng qua ma\- tinh dua tren phAn mlm vilt bing Visual Basic (VB) Nhan quang dien cu dugc thay thd bing nhan quang R-928 cua Hamamatsu (Japan) de md rdng vung nhay phd Cac phep ban diu dugc tien hanh nham muc dich can chinh va xac dinh chd hoat dgng.Sau cai tien ihanh cdng xk thiet dai chuan cho he ma>- quang phd mai chung toi da xay dung cdng mdt he thu Raman kich thich bang laser Argon cong suit 0.5 W Nhd thay nhan quang dien mdi chung tdi da cd the thu dugc Raman cua chiet phim diu md kfch thich bing laser He-Ne cdna suat 30mW Day la mot thuan Igi Idn vi tranh dugc phdng huynh quang phd Raman va khong phai lam lanh laser nhu dung laser Argon He thu phd mdi thd hien nhieu tien bg nghien cuu cac phd huynh quang \-a phd Raman cung nhu cac phd tin hieu yeu ndi chung H - BO TRI THirC NGHIEM VA KET QUA Cau triic cua he thu phd cai tien Signal In CPU ^ LPT Port I GPIB B interface lock-in ainj)lifier ! Spectral, : V Siignal ; ill GDM -1000 Chopper Signal Step Motor ¥ u^ t c ^- jw • - J ' ^- ^ Hmh 1: Sa ao khoi cua he thu aa duac y ^ • nang cap Hinh 2: Sa quang cua mdy doii sac GDM-1000 I-Khe vao; J - GuoTig; - Chopper; ? ^ /- - / , • - z^j 3,6 - Cach tu; / ~ Khe Sa dd khdi cua he thu phd cai tien dugc bieu dien Hinh May dan sac GDM-1000 bao gdm hai each tu 650vach/mm, vung phd hoat ddng tu 7500 - 16675 cm'' (ung vdi phd bac nhat) va tu 16675 - 28700 cm'' (umg vdi phd bac hai) Hinh bieu dien sa dd quang ciia may GDM-1000 Bd phan tu ghi dugc thao thay vao sd lieu dugc luu tru \k xir ly bang may tinh ca nhan (PC) Mdt md ta budc l,8%udc dugc lap vao \'i tri thich hgp de quay each tu chgn budc sdng Mdt budc nhiy cua mota lam thay ddi sd sdng la 0.0832cm' De dieu khien md ta budc chuong trinli dieu khien se giri mdt day cac sd nhi phan bdn bit qua cdng song song (LPT) cua may tinh theo thu tu: 0001; 0011: 0010; 0110; 0100; 1100;^1000^; 1001 tuang ung vdi cac \\ tri budc ^ -> ^ ->5 -^6 -^1 ->8 [3] Cac tin hieu chi la cac muc logic TTL nen can phai cd mdt bd dem trudc dua d^n mo ta budc Nhan quang dien M12FC (head-on) cua may ghi phd GDM-1000 nhay \di viing buac sdng 400-500nm (hinh.3a) Vdi \'ung budc sdng cac phep phd huynh quano cung nhu Raman bi han che rat nhieu Nham md rdng \-ung dap ung budc sdn^rnhan quang dien R-928 (side-on) ciia Hamamatsu da dugc lua chgn tha\ th6 cho^M12FC (head-on) Dac trung dap irng phd cua R-928 dugc cho tren hinh 4b Nhan quang R-928 su dung photocathode phan xa lam bang \at lieu multialkalin bo nhan dien tir cd ciu true Idng trdn dap irng phd rong (185-190nm> nha\- cathode cao (74mA/W tai 400nm) ciing vdi cac dac trung tri va trdi theo thdi gian rat thap Bg phan chia the va ngudn cao ap cung cap cho nhan quang R-928 dugc cau tao mdt bg de cam hieu C6270 - Hamamatsu Dd cim C6270 diing neudn nudi 15 Vdc va tao the cao ap cd the lap trinh dugc tir ddn 1250 Vdc Thd cao ap d ldi dugc lap trinh bang viec thay ddi dien ap ldi vao didu khidn tir ddn Vdc, dac trung lap trinh ciia C6270 cd tuydn tinh rit cao, thdi gian dap img nhanh va dd eon the nhd I.OKIO' \ e.oxio" \ 6.0x10"' IS il 4.0K10'' V.^_ 2.0K10"' 0.0 400 450 500 550 600 bJdc s6ng(nm) IS 650 700 •ID: ICO jcc 40O soc- eca '*VAV=LEN0~H &X io& 103: T-.r Hinh 3: Do nhay cua nhdn quang MI2FC (a) va nhdn quang R-928 (b) Tin hieu phd tir nhan quang dugc dua den bd khuyech dai lock-in SR830 Sa dd khdi cua SR830 dugc cho tren hinh SR830 la mot bd khuyech dai lock-in sd sir dung bd xu ly tin hieu sd Motorola 24-bit DSP56001 va vi xir ly 80C186 Tin hieu ldi vao sau dugc tien khuyech dai dua den bd ADC chuyen sd SR830 cd the tu phat tin hieu Reference (ref ndi) hoac dimg Referece ngoai fref ngoai - thudng den tir chopper) rdi diing mdt vdng bam pha (PLL) de tao tin hieu sin thuan nhat, tiep dd dua vao bd tao ham sin Sau dd ca hai tin hieu sd dugc dua ddn bg DSP tai day cac thuat toan lock-in dugc thi hanh mot each hoan toan ly tudng Trong DSP cung chira cac bd Igc sd giiip thi hanh chirc nang Igc tan ma khdng cin cd cac mach Igc RC nhd vay cd the loai bd meo dung cu Ket qua sd cua phep nhan lock-in dugc liy nhd giao difn RS232 hoac giao dien GPIB, ket qua nav cung dugc dua tai bd bidn ddi DAC dh cd the lay a ldi tuang tu (Analog Output) Toan bd hoat dgng cua lock-in SR830 dugc dieu khien thdng qua cac chuin RS232 hoac GPIB (IEEE-488) Viec aiao tidp giiia may tinh va SR830 sir dung cac ky tu ASCII Mdi lenh tdi SR830 bao R6m k7 tu ggi nhd cac ddi sd can thiet, va mot dau ket thiie lenh Dua tren nauyen^tic chiing tdi da \\k mot phan mdm bang ngdn ngir Basic chay iren PC dfdidu khi^n va thu thap xir ly so lieu tir bd lock-in SR830 Sd lieu nhan tiilock-in dugc luu tru \k bilu dien true tilp dd thi hien thi tren man hinh qua trinh Giao dien sir dung ciia chuong trinh na\- dugc minh hoa dudi da>- Low Noise Differential Amp 50/60 HZ Notch Filter 00120 HZ Notch Filter Gain \'oItage -^ B Current I DC Gain Offset Expand YOut Reference in XOut Discriminator Sine Out TTL Out Discriminator Hinh 4: Sa khoi cua khuyech dai lock-in SR830 rrj[^i Hinh 5: Giao dien cua chuarig trinh Cac phep Chiing tdi da tidn hanh mot sd phep phd de xac dinh che hoai dgng \a can chinh he \\ du nhu phd huynh quang ciia ZnS pha tap Mn phd tan xa Raman ciia ciia cac H\drocarbon thong thudng kich thi'ch bang laser Argon \a laser He-Ne Cac phep cho thiy he phd mdi dat dugc nhay va phan 2iai cao cd nhidu tien bo \-iec thirc hien cac phep phd huynh quans va Raman " " " " ^ (a) tAO CDOC D«D : » ! IC (d) ist; t:ằ;i :.OTIO n 1.ôi IC i\ 'ằ:ô" mot I 1-0' 10 i.tj to " ia»oo iJOOG li.oo i«oo 14-5': ///«// 6: Pho Raman cua cdc mdu ddu wo a- Mdu 5B} 10 kich bang laser Argon; b- Mdu 5B110 kich bdng laser He-Ne c- Mdu 5B115 kich bang laser Argon; b- Mdu 5B115 kich bdng laser He-S'e Chiing tdi da cdng viec thu phd tan xa Raman ciia cac chiet phan dau md kich thich bang laser He-Ne 30mW Do nhay cao cua he vimg dd \'a viing hdng ngoai dem lai kha nang nghien cim phd Raman cudng kich thich yeu, sir dung cac laser He-Ne cdng suat trung binh thay cho laser Argon-Ion cdng suat Idn lam lanh bang nude, dieu giup cho vide nghien cim quang phd Raman dien dan gian va tiet kiem Hon nira, \iec su dung cac ngudn kich budc sdng dai nhu laser He-Ne de nghien Raman giup tranh dugc cac dam phd huynh quang thudng gap phai sir dung cac ngudn kich budc sdng ngan cdng suat cao nhu laser Argon-Ion Cac phep dugc tien hanh cho thay khdng cd su xuat hien ciia dam huynh quang phd Raman kich thich bang budc sdng 632,8 nm cua laser He-Ne Khi kich thich bang laser Argon gan vimg tir ngoai cd the tao phd huynh quang chdng len phd tan xa Raman Dieu dugc the hien rd rang nghien ciru tan xa Raman ciia cac mau dau md 5B110 ^•a 5B115 (chiet pham dau khai thac tir md Bach Hd Viet Nam) Phd tan xa Raman kich thich bang Laser HeNe xuit hien nhidu dinh Raman haii cho nhieu thdng tin hon \e mau \at, ^o \-di trudng hgp kich thich bang laser Argon (hinh 6) HI - KET LUAN Tir mot may ghi ph6 each tu kep GDM-1000 (Carl Zeiss, Jena, CHDC Dire) chiing tdi da nang cip tang nhay ciing vdi vimg quet phd rdng ban (400-900nm) va chuyen ddi cong mot he phd phan giai cao kdt ndi may tinh sir dung ky thuat lock-in Day la mot giai phap kinh te, rat phii hgp cho cdng \iec nghien cim va dao tao trudng dai hgc He quang phd mdi nang cip cd thd thu dugc cac tin hieu quang yeu, nhu phd tan xa Raman ciia cua miu diu md Viet Nam kich thich bang laser He-Ne 30 mW thay vi phai sir dung laser Argon - Ion nhu trudc day Phd Raman kich thich bang laser He-Ne cd rit nhidu Igi thd so vdi kich thich bang laser Argon-Ion Cac ket qua budc diu hua hen kha nang sir dung he thu phd cac nghien cuu tinh chat cua vat lieu bang hieu img quang phi tuydn tuang lai LCJI CAM ON Cdc tdc gid chdn cdm an su hd tra cua Chuang Trinh Nghien Cicu Khoa Hoc Tu Nhien ciia Dai hoc Quoc gia Hd noi vd Chuang Trinh Nghien Cuu Khoa Hoc Ca Bdn Quoc Gia cho nghien cuu ndy TAI LIEU THAM KHAO Nguyen The BinhAdvances in Photonics and Applications, (2004) 75-81 Proceeding of the Intemational Workshop on Photonics and Applications Hanoi (IWPA2004) 2.Takeshi Kitahara, Goro Mizutani Journal of Applied physics Vol 95 No9 (2004) Bhaskar Gupta,Understanding various types of Stepper Motors And Controlling it through Parallel Port, Homepage: http://collection.sharewith.us (2004) Stanford Research Systems, Model SR830 DSP Lock-in Amplifier, (1993) 5.1 - 5.34 Halina Baranska: Laser Raman spectrometry, John Wiley& sons Warsaw 1987 ABSTRACT We studied to improve an old Double Grating Spectrograph GDM-1000 (Carl Zeiss Jena, Germany) which operates v.ith self-recorder for a high resolution spectrometry system coupling with computer using Lock-in amplification technique In order to get high sensitivit}' in v^'ider range of w^avelengths we replaced the M12FC PMT by a side-on R-928 PMT (Hamamatsu) and detected PMT signals by a digital signal processor (DSP) lock-in amplifier (Model SR830, Stanford) A stepper motor with suitable design and construction was connected A compatible control and data- acquisition program was written for the new spectrometr}' system Several measurements were carried out to determine the operation regime and calibration We succeeded in obtaining Raman spectra of petrol extracts by 30mW He-Ne laser excitation Our new spectrometr>- s}-stem shows man}' advantases for studying Raman and Fluorescence spectra as well as weak optical signal spectra Tn general This is an economic solution and ver\' suitable for teaching and research in Universities Bdo cao tai Hoi nghi Vat ly toan quoc lan (hit VI, Hd Noi 23 -25/11/2005 S I ; PHAT QUANG CUA TINH THE ZnSe Pham Van B§n , Bui Hong Van Khoa Vat ly ,Trudng Dai hoc Khoa hgc Tu nhien, Dai hgc Quoc gia Ha Ndi 334 Nguyen Trai, Thanh Xuan , Ha Ndi Phd phat quang ciia tinh the ZnSe dl3K dugc kich thich bing cac budc sdng 365nm va 450nm cua den Xenon chi xuit hien nhirng vach^va nhiing dam phat quang d viing xanh lam tir 450nm ddn 500nm va xanh la cay vdi cue dai d 570nm Cac vach va cac dam dac trung cho tai hgp bue xa cua exciton lien ket tren cac nut khuydt cua Zn (Vzn) vdi su tham gia ciia cac phonon quang LO, cac cap donor-acceptor ndng va tap chit Khi tang nhiet do, cudng cua cac vach va cac dam ddu giam Ci 300K, tinh the ZnSe dugc kich thich bang budc sdng 488nm cua laser Argon vdi mat nang lugng kich thich tir 4.2w/cm^ ddn 33.7 \v/cm^, phd phat quang xuit hien mdt dam rdng d viing da cam - dd vdi cue dai dich chu\'§n v6 phia nang lugng Idn (khoang 11 meV) Dam dac trung cho tai hgp birc xa ciia nhirng cap donor ndng va acceptor sau d gan I MO DAU Phd phat quang cua tinh the ZnSe d viing xanh lam tir 13K ddn 300K da dugc nghien cim nhieu O viing phd nay, ngoai cac vach dac trung cho su tai hgp birc xa ciia cac exiton tu do, exciton Hen ket tren cac donor, acceptor cdn xuat hien cac dam rdng dac trung cho tai hgp bue xa cua cac cap donor-acceptor ndng [1.2.3.4] Tuy nhien phd phat quang ciia tinh the ZnSe d vimg xanh la cay va viing da cam - dd dugc nghien cim it \a ban chat birc xa ciia cac dam dugc giai thich kliac [2,4] Nham lam sang td mdt \'ai ca che tai hgp biic xa va kha nang img dung ciia tinh the ZnSe cac N'iing phd nay, chiing tdi da tien hanh nghien ciru phd phat quang ciia tinh the ZnSe tir 13K den 300K vdi nhirng mat nang lugng kich thich khac IL MAU NGHIEN ClTU VA THIET BI THlTC NGHIEM Tinli the ZnSe dugc nudi bang phuang phap ndng chay vimg Vien Han Lam YOOE chi tao Phd phat quang ciia nd tir 13K den 300K dugc kich thich bing doi Xenon XFOR-450 , laser Argon 237A va dugc ghi tren cac phd ke FL3-22 GDM -1000 vdi khudch dai lock-in SR830 ( D - 5A%im) III KET QUA VA BIEN LUAN l.Pho phat quang cua tinh the ZnSe Hinhla lb la phd phat quang ciia tinh the ZnSe tii" 13K den 300K kich thich bing cac budc sdng 365nm va 450nm ciia den Xenon pvbeiikhth@y'ahoo.com Bdo cao tai Hoi nghi Vat ly toan quoc Idn thu VI, Hd Npi 23 -25/11/2005 1200000 450 500 550 600 Wavelength (nm) 650 700 450 500 550 600 650 Wavelength (nm) 700 Hinh la, lb : Pho phdt quang cua tinh the ZnSe kich thich bdng buac song 365nm vd 450nm cua den Xenon tic 13Kdin 300K O 13K, gan bd viing cam xuat hien hai vach hep vdi cudng manh d 456nm va 461imi nam tren nen cua dam phat quang mau xanh lam tir 450nm d6n 500nm \'di cudng yeu hem Hai vach la nhirng vach lap lai phonon quang (J^ - 2L0) \a (JA-3L0) cua vach ecxiton lien ket JA tren cac niit khuyet eua Zn (V^^) vdi nang lugng phonon ELo^30meV[l,2,3,4,5] Gia tri phii hgp vdi nang lugng ELQ rna chiing tdi thu dugc d phd microRaman cua tinh the ZnSe (EL,o^31.4meV)(hinh 2).C) day vach JAva (JA -LO) khdng xuat hien cd the su hap thu manh d gan bd viing cam Khi tang nhiet do, cac vach va dam phat quang tat rat nhanh su phan huy cac trang thai ecxiton Ban chat ciia dam phat quang xanh lam d 300K la sir tai hgp birc xa ciia cac ecxiton lien ket tren cac donor ndng khdng kiem tra dugc nhu: Al Ga, In [2] hoac cua td hgp ecxiton tu \ a chuyen ddi \'iing - viing [5] () vimg nang lugng thap, kich thich bang budc sdng 450nm ciia den Xenon, phd phat quang ciia tinli the ZnSe cdn xuat hien mdt dam rdng d viing xanh la cay vdi cue dai d 570mn Dam khdng ddi ximg, sudn ben trai ddc hon sudn ben phai.Khi tang nhiet tir 13K den lOOK, cudng cua dam bi giam nhung vi tri cue dai ciia dam tha\' ddi rat it, \i the chiing tdi xem rang dam cd the dac trung cho chuyin ddi biic xa xay mdt tam tap chat cd tinh the ZnSe [3.4] 300K kich thfch bing budc sdng 488nm ciia laser Argon, phd phat quang ciia tinh thi ZnSe xuit hien mdt dam rat rdng cd cue dai d 606nm (hinh 3) Do dam ma sudn ben phai cua dam d 570nm thoai hon sudn ben trai cua nd Su' phu thuoc vi trf va cuong cua dam phat quang viing da cam - d 606nm vao mat nang luong kich thich Khi thav ddi mat nang lugng kich thich ciia \ach 488nm cua laser Argon tir 4.2 \v/cnr ddn 33.70 w.'cnr vi tri cue dai ciia dam 606nm bi dich chu>'en \-e phfa nang lugng Idn khoans ImeV va rdng ciia dam tang len khoang 48meV (hinh 4j Day la dac trung didn hinh ciia tai hg]5 bii'C xa donor- acceptor Klii mat nang lugng kfch thich nhd cac hat tai dien sinh ft dd birc xa ga>' nen chu > eu bai nhirng cap pvbeiikhth@}'ahoo.con: Bdo cao tai Hoi nghi Vdi ly toan quoc lan thu VI, Hd Npi 23 -25/11/2005 donor - acceptor d xa vdi nang lugng nhd Khi tang mat nang lugng kfch thich nhung cap donor- acceptor d xa bat dau bao hoa, nhirng cap donor - acceptor d gan \ di nang lugng Idn dugc tang len [2] Vi the tang mat nang lugng kfch thfch, vi tri cue dai cua dam donor-acceptor dich chuyen ve phia nang lugng Idn \a cudng ciia dam ciing tang len Cudng cua dam 606nm phu thudc vao mat nang lugng kich thich theo quy luat Jhq= Jki" vdi n ^ 0.6 (hinh 5) 2.0x10"' e a J =4,2w/cm* 6D6 1.8x10"* c J^=21 Ow/cm' I.SxIO"* d: J^=25.3w/cm' 3.1.4x10"* e J =33,7w/cm' 11.2x10I 1.0x10-' r^ "^ 8.0x10"* 606 48 '' 6.0x10"* 4.0x10* 2.0x10'* 200 300 400 600 &00 Wavelength 620 680 (nir; Hinh 3: Pho phdt quang cua tinh the Hinh 2: Pho microRaman ciia tinh the ZnSe ZnSe vai cdc mat ndng luang kich kich thich bdng buac song 632.8 nm cua thich khdc kich thich bdng buac laser He-Ne a 300K song 488nm cua laser Argon a 300K 2.0 2.5 3.0 3.5 1.5 2.0 2.5 Energy density (w/cm') Hinh 4:Suphii thuoc vi tri cue dai dam 606 nm cua tinh th^ ZnSe vdo mat ndng hcong kich thich a 300K Hinh 5: Su phu thuoc cuang ddm 606nm cua tinh the ZnSe vdo mat ndn^ hrcmo- kich thich a 300K Vai nhijna dac diSm tren chung toi xem rSng dam phat quang a \ img da cam-do voi cue dai a eo'enm la tai hgp biic xa cua nhung cap donor nong \a acceptor sau a dn nhau.'trong donor nong co ihl la Al [4] ^•a acceptor sau la cac nut khu>et cua Zn lien kStvoi^Cl (Vzn-Cl)[6] pvbenkhth@yahoo.com Bdo cao tai Hoi nghi Vdi ly toan quoc lan thu VI, Hd Npi 23 -25/11/2005 IV KET LUAN Ddi vdi tinh thd ZnSe, kich thich bing cac budc sdng 365nm va 450nm cua den Xenon thi phd phat quang cua nd xuat hien eac vach va cae dam d \iing xanli lam tir 450nm den 500nm va xanh la cay d 570nm Khi kich thich bang budc sdng 488nm cua laser Argon vdi mat nang lugng tir 4.2 w/cm' den 33.7 w/cm~ thi phd phat quang ciia no xuit hi?n dam 606nm d viing da cam-dd Do cd iY\k diing tinh the ZnSe de che tao cac didt phat quang cac vimg phd TAI LIEU THAM KHAO Bo^5omeHKO.B.3,BaBU7ioB.B.C.OTn, 21(1987) 191-193 B.C.BaBu^oB By 3oaH M-ben, 26 (1984) 1457-1462 B.H.raBpH.ieHKO, A.M.FpexoB.OnTMHecKHe CBoi^CTsa ^o.^y^poBo;lHHKOB,(I987) 429-439 C.B.ranoHCHKO, B.n rpuOKOBCKMH 4oK7ia4bi AKaAeMiifi m\^ BCCP 28n984) 318-320 r.H.MBaHOBa fl-fl.Hegeoro.io.OTn,]4(1980) 31-35 Keizo Morimoto J.Appl physis, 64(1988) 4951-4955 K.M.Lee.Le Si Dang and G.D.Watkins, Solid State Communication,35( 1980) 527- 530 Yong-Sik lim, Seok - Chan Yoon, AppHed physics letters, 82(2003) 2446-2448 O.V.Vakulenko, V.M.Kravchenko, Functional Materials, 11 (2004) 90-94 Abstract : Using the wa\'elength of 365nm and 450nm of Xenon lamp to excite ZnSe cr\'stal at temperature about 13K, the luminescence spectra shoNsed light blue band from 450nm to 500nm and green band having maximum peak at 570nm These bands and lines charactered for radiati\'e recombination of ecxiton bond Zn vacanc\- (V^n) with the contribution of LO phonon, shallow donor-acceptor pairs and impurity The intensity of these bands and lines increased with decreasing temperature At 300K \\Tien the ZnSe crystal was excited b}- 488nm of Ar laser with the energy densit}" from 4.2w/cm"^ to 33.7w'cm^luminescence spectra showed an wide orange-red band ha\ing maximum peak shifted to\Nard high energy (up to 11 meV) These bands charactered for radiative recombination of near neighbour shallow donor- deep acceptor pairs pvbenkhtn@yahoo.com p\benkhth@>'ahoo.con- DAI HOC QUOC GIA HA NQI KHOA Sir PHAM BUI HONG VAN Si; PHAT QUANG CUA BAN DAN VUNG CAM RONG ZnSe K m KICH THICH BANG DEN XENON VA LASER KHI ARGON KHOA LUAN TOT NGHIEP HE DAI HOC CHINH QUY CHUYEN NGANH : QUANG LU3NG TlT HUCiNG DAN KHOA HOC : TS PHA-M VAN BEN HA NOI - 200, Vf i>'' DAI HOC QUOC GIA HA NOI TRl/CJNG DAI HOC KHOA HOC TU NHIEN KHOA VAT LY >!: A A S I ; PHAT QUANG CUA BAN DAN VUNG CAM RONG ZnS KHI PHA TAP Mn KHOA LUAN TOT NGHIEP HE BAI HOC CHINH QUY Chuyen nganh :Quang Lucmg tu Sinh vien : Hoang Van Han Hu6n^ d^n khoa hoc TS Pham Van Ben Ha noi - 2005 DAI HOC QUOC GIA HA NOI TRUC)NGDAIHPC KHOA HOC TU NHIEN - KHOA SUPHAM KHOA VAT LY NGUYEN THI TIEN PHO TAN XA MICRO - RAMAN CUA BAN DAN VUNG CAM R O N G Ziii.Fe.Se (x: ^ 0,1727) KHI KICH THICH BANG LASER KHI He - Ne Giao vien hirdng dim TS PHAM VAN BEN Sinli vien thirc hien NGUY6N THI TIEN Ldp B3K46SUPHAMLY HA NOI, 2005 PHIEU D A N G K Y K^T nnk MHRIPM CUU KHOA HOC - CONG NGHE Nghien cmi cac tinh chat quang cua hop chat Ten de tai ban din vung cam rong QT- 05 - 08 Ma so Ca quan chu tri de tai Dia chi Tel Co quan quan lydd tai Dia chi Tel Truong Dai hoc Khoa hoc Tu nhien Nguyln Trai - Thanh Xuan - Ha noi (04)8584287 Dai hoc Quoc gia Ha noi 144 Duong Xuan Thiiy, Cau giay, Ha noi Tdng kinh phi thuc chi Trong do: 20.000.000 d -Tiirngan sach nha nuac -Kinhphicuatnrons - Vay tin dung 20.000.000 d Khong Khong Khong Khong - Von tu CO Thu hoi Thoi gian nghien cuu Thai gian bdt dau Thai gian ket thiic 01 nam 8/2005 8/2006 ThS.Hoang Chi Hieu Ten can bo phoi hap nghien cuu CN Nguj'in Thanh Chuang CN Nguyen Anh Tuan 73~ ,, " So' chung nhan dang ky I Bao mat So dang ky de tai ket qua ' a) Phd bien rong rai , bj Phd bien han che ; c) Bao mat Tom it ket qua nghi&n cUu: / Trni hieu ly thuyd't ve tinh cha't quang cua cac hap chat ban din viing cam rdng / xay dung he kfch thfch, thu phd huynh quang va tan xa Raman tren ca sof may dan sac each tii kep GDM - 1000 va ky thuat Lock- in ^ Thu va nghien cun phd huynh quang cac hap chat ban dSn viang cam r6ng nhu: ZnSe, ZnS, va ZnS:Mn Kien nghi ve quy mo va doi tugfng ap dung nghien cuu: - Can phd a nhiet thap - Phuc vu cho cac Cong ty dien quang Chu nhiem de tai Ho va ten Pham Van Ben Hoc ham hoc vi Tien si Kyten dong dau Thii truong co quan chii tri de tai fr.'iO Chu tich hoi dong danh gia chfnh thuc L l^fl^'d ^/'^^Ki Thii truang ca quan quan ly de tai !fc tjAK fC:CA }•:.:>[ :;: \\ ... rong rai cac dung cu quang dien tu Chiing dung de che tao cac di ot phat quang, quang tra, nhung cua so suot viing kha kien va hong ngoai gin [1, 2, 3, 4] Trong ph6 phat quang cua cac hgp chat... vd thu phd huynh quang, tdn xa Raman tren ca sd mdy dcm sdc cdch tu kep GDM -1000 diing ky thuat lock - in a Md dau b He kfch thfch huynh quang va tan xa Raman c He thu huynh quang va tan xa Raman... huynh quang va tan xa Raman e Ket luan 3, Nghien citu tinh chdt quang cua bdn ddn viing cdm rong ZnSe a Ma dau b MSu nghien ciJu va thiet bi thuc nghiem c Cac ket qua va bien luan ^ Pho phat quang