Tiiu ban Khoa hoc vdt lieu ISBN 978 604 913 0 CHAT NHAY QUANG RUTHENIUM (II) BIPYRIDINE CHITA NHOM CHlTC CACBAZOL iTNG DUNG CHO PIN MAT TRC>I CHAT MAU NHAY SANG HIEU SUAT CAO Nguyen H6ng Minh, Nguyen[.]
Tiiu ban Khoa hoc vdt lieu ISBN: 978-604-913-0: CHAT NHAY QUANG RUTHENIUM (II) BIPYRIDINE C H I T A NHOM CHlTC CACBAZOL iTNG DUNG CHO PIN MAT TRC>I CHAT MAU NHAY SANG HIEU SUAT CAO Nguyen H6ng Minh, Nguyen Due Nghia Vien Hda hpc, 18 Hoang Quoc Viet, Cau Giay, Ha Ndi Email: ducnghia264@fpt.vn Tom tat Phiic chdt Ruthenium (II) dgng cis-fRii(H2dcbpy)(L)(NCS)2], H2dcbpy Id 4,4'-dicarboxy-2,2'-bipyridine vd L la 4-(4-carbazole-9-yl-styryl)-4'methyl-2,2'-bipyridine (Rut-Bl), vd 4-(4'-(3,6-dihexyloxycarbazole-9-yl)-styryl)4 '-methyl-2,2 '-bipyridine (Rut-B) dd dugc tdng hgp vd nghiin cuu dnh chdt Hiiu sudt cita pin mat trdi Ti02 dua trin nhiing chdt mdu ndy dd dugc^ nghiin citu Hiiu sudt tdt nhdt thu dugc su dung chdt mdu Rut-B cho hiiu sudt chuyin hda 6.I%o diiu kiin AM I.5G Chudi ky nude alkoxy a vi tri vd trin carbazole cd tdc dung ldm chdm qud trinh chuyin diin tich viing ddn cita^ Ti02 vdo chdt diin ly (If) Hiiu sudt vugt trdi cita chdt mdu Rut-B Id cd hi sd ddp tdt cao, ngdn chdn hiiu qud tdi hgp diin tich vd cd muc ndng lugng phii hgp Abstract Heteroleptic ruthenium(II) complexes cis-[Ru(H2dcbpy)(L)(NCS)2], where H2dcbpy is 4,4'-dicarboxy-2,2'-bipyridine and L is 4-(4-carbazole-9-yl-styryl)-4 'methyl-2,2 '-bipyridine (Rut-Bl), and 4-(4 '-(3,6-dihexyloxycarbazole-9-yl)-styryl)4'-methyl-2,2'-bipyridine (Rut-B) have been synthesized and characterized The performance of these dyes as photosensitizers in nanocrystalline Ti02 based solar cells was also investigated The best photovoltaic performance was obtained by Rut-B based solar cell yielding a power conversion efficiency of 6.1 % under AM I.5G conditions The hydrophobic alkoxy chains at the 3,6-positions of carbazole appear to help retarding the charge transfer from the conduction band of TiO2 to the electrolyte If The particular efficiency of Rut-B is attributed to the high molar extinction coefficients, effective charge recombination suppression and favargble energy levels I GI61 THIEU Pin mat trdi chat mau nhay sang (DSSCs) dua tren phiic ruthenium da thu hiit nhilu mdi quan tam sau cd nhung cdng bd ciia Gratzel va cpng sir [1,2] Hien tai, nhirng chit nhay quang ruthenium nhu N3, N719, chit mau den cho hieu suit cao nhit, (r\) dat tdi 7-9 % [3,4] Trong mpt DSSC dien hinh photon dupe hip thu bdi chit nhay quang va dien tu tir trang thai kich thich ciia chat mau truyen vao dai dan ciia chit ban dan cd cau true nano (anatase Ti02, ZnO) De cd hieu suat chuyen boa cao, phirc ruthenium can dugc thilt kl cho cd hieu suat truyen dien tir cao, tach dien tich hieu qua de lam cham su tai hgp, ciing nhu la cd mirc nang lupng HOMO-LUMO phii hgp va tai tao trang thai ban dau hieu qua tir trang thai da bi oxi boa Trong nhiing nam gan day, nhiing hgp chit di vdng nhu pyrol, thiophen da dugc ghep vao ligand bd sung ciia phirc ruthenium bdi chiing cd dp ben tdt, dai hap thu dich vl 'Ma budc sdng dai [5-7] Hgp chat di vdng thudng cd dp dich chuyen dai hap thu vl phia b ,c 238 Hoi nghi Khoa hgc ky niim 35 ndm Vien KH&CNVN-Hd Noi -10/2010 sdng dai tdt ban so vdi benzene [8] Cacbazol dugc biet din nhu la mdt phan tir cd cau tnic phing, giau dien tir, va da dugc sir dung rpng rai vat lieu polymer quang dan [9] Hon nira, nhimg polyme cd viing cim hep mdi dira tren cacbazol da cho thay nhirng trien vpng kha quan cho nhiing iing dung quang thi [10] Cacbazol cd the dugc sir dung nhu tac nhan cho dien tir de cai thien hieu suit cua DSSCs Gan day, cacbazol da dugc dung nhu tac nhan cho dien tir chit mau hiru co va hieu suit pin mat trdi dat dugc 6-8.3 %> [11-13] Cho den nay, nhirng cacbazol thi d vi tri 3,6 lien ket phiic ruthenium van chua dugc cdng bd Dua tren nhiing dir kien tren, chiing tdi da thiet ke va tdng hgp mdt sd ligan mdi de nhan dugc phiic ruthenium phii hgp cho DSSCs Chat nhay sang cd cdng thiic cis[Ru(H2dcbpy)(L)(NCS)2], dd H2dcbpy la 4,4'-dicarboxy-2,2'-bipyridine va L la 4-(4carbazole-9-yl-styryl)-4'-methyl-2,2'-bipyridine (Rut-Bl), va 4-(4'-(3,6-dihexyloxycarbazole-9-yl)-styryl)-4'-methyl-2,2'-bipyridine (Rut-B) da dugc tdng hgp va nghien cim tinh chat Ligan (L) dugc tdng hgp bdi cacbazol lien ket vdi ligan bd sung dua tren gia thiet sau: cau tnic phang ciia cacbazol lam tang hieu qua dp dai lien hgp cua he thdng dien tir n Anh hudng ciia hai ligan len tinh chat boa ly va hieu suat ciia DSSCs dua tren chat mau tdng hpp ciing da dugc nghien ciiu II KET QUA VA THAO LUAN Cau tnic ligan va phiic ruthenium Rut-Bl, Rut-B dugc chi tren Hinh Qua trinh tdng hgp ligan Bl va B gdm nhieu giai doan vdi chat dau la cacbazol [15] Budc tiep theo la tao nhdm chirc andehit bang phan iing Vilsmeier-Haack Trong trudng hgp ligan B, Nphenylcacbazol dugc chuyen hda 3,6-dibromo-N-phenylcacbazol bang phan img brom hda vdi tac nhan N-bromosuccinimit [16] Chat trung gian sau dd dugc phan iing vdi Natri va «-hexanol de tao dan xuat d vi tri 3,6 ciia phenylcacbazol Hop chat sau dd cho phan img vdi tac nhan POCI3 de tao nhdm chiic andehit Hai ligan dupe tdng hgp bdi hai budc: phan img cpng nucleophin eiia anion dimethyl bipyridin vdi andehit trung gian, tiep theo la phan iing loai nude axit axetic dun hdi luu Phan img tdng hgp phirc ruthenium dugc tien hanh theo phuang phap tieu chuan ciia Gratzel va cpng sir [ 14] Ligan B1 (hoac ligan B) va dichloro (p-cyvacn) ruthenium (II) dime dupe dun ndng dimethylfoocmamit (DMF) d 80 C, sau dd them vao 4,4'-dicacboxy-2,2'-bipyridin va dun hdi luu tao phiic trung gian Cudi cimg, lugng du ciia NH4NCS dugc them vao de tao ligan thiocyanat lien ket vdi N San pham thd dugc tinh che bang cot Sephadex LH-20 vdi metanol lam dung mdi Phiic chat dugc phan tich cau tnic bang phd UV-Vis, phd khdi va cpng hudng tir hat nhan Rut-B Hinh 1: Cdu true ligan vd phitc Rut-Bl, Rut-B Phd UV-Vis ciia chit nhay sang DMF (ca 1.23 x lO'^M) dugc chi tren Hinh 2a Chat mau Rut-Bl cd cue dai hip thu d 291 nm, 369 nm, va 527 nm Cue dai tai 291 nm 239 ISBN: 978-604-913-0!'-3 Tiiu ban Khoa hgc vdt liiu dac tnmg cho sir chuyen mirc n-n* ciia bipyridin Cue dai thir hai d 369 nm dac trung cho chuyen mirc n-n cua ligan Bl va mdt phan cua chuyen mirc dien tich tir kim loai den ligan (MLCT) Cue dai tai 527 nm dac trung cho MLCT gay nen bdi ligan NCS Nhiing cue dai hip thu tuong tir cung xuit hien vdi Rut-B tai 294 nm, 384 nm, va 535 nm Dai cd nang lupng 70 ' I I 1 (a) O 60 Rut-Bl E " 50 t 3D (/) '^ »1 -ll 1 1 Rut-B ' 1 \ f \ , 'v \ \ 20 - \ \ _ 'O- \ Q \ \\ 300 350 400 450 500 550 Buac song (nm) 6C0 650 700 400 450 500 550 600 650 700 750 Buac song (nm) Hinh 2: Phd hdp thu cita Rut-B I vd Rut-B irang DMF (g) hdp phu trin mdng Ti02 (b) thap nhat MLCT ciia Rut-B dich chuyen ve phia budc sdng dai nm so vdi Rut-Bl va cd he sd dap tat tai 535 nm la 20760 M"'cm"', cao ban Rut-Bl vdi 17300 M"'cm"' Sir dich chuyen ve phia budc sdng dai ciia MLCT va cd he sd dap tat cao hon bdi sir tang cudng chuyen vi cua dien tir n gan chudi hexyl oxi len cacbazol [17] Phd hap thu cua nhirng chat nhay sang len mang Ti02 pm dugc chi tren Hinh 2b Chat mau Rut-Bl va Rut-B cd dac trung phd tuong tu nhu dung dich nhung cue dai hap thu dich chuyen nhe ve phia budc sdng dai sir dich chuyen mirc nang lugng ciia chat mau hap phii len Ti02 Tinh chat dien hda cua Rut-Bl va Rut-B dugc nghien ciiu bang phuang phap phd dien the tuan hoan (CV) Do dac CV dugc thuc hien dung dich BU4NBF4 (0.1 M) DMF vdi tdc dp quet 50 mV/s Dinh oxi hoa khdng thuan nghich dac trung cho Ru^"^''^^ dd thi oxi hda ciia Rut-Bl la 0.79 V, Rut-B ciing cd the oxi hda tuong tu (0.76 V vs Ag/AgNOs) hai phirc cd cau true tuong tu Mirc nang lugng HOMO, LUMO va viing cim dua tren the oxi hda, phd hap thu va phat xa dugc xac dinh va tdm tat tren Bang Muc nang lugng HOMO dugc xac dinh d mirc -3.0 eV so vdi miic chan khdng, cho thiy miic nang lugng cao hon day dai dan cua Ti02 (-4 eV, -0.5 V vs NHE) Qua trinh truyin dien tir tir chit mau vao dai dan ciia Ti02 la thuan lgi ve mat nang lugng [18] Bdng 1: Tinh chdt qugng vd muc ndng lugng ciia chdt mdu ruthenium Do hap thu XMLCT /nm Phat xa V^^^^ HOMO LUMO (ex 10^M"'cm'') I^m/nm [eV] [eV] (V) Rut-Bl 527(17.3) -5.41 612 0.79 -3.02 Rut-B 535 (20.76) 0.76 -5.38 628 -3.0 E^^ [eV] 2.39 2.38 Pin mat trdi chat mau nhay sang dugc chi tao sir dung Rut-B 1, Rut-B lam chit nhay sang cho dien cue Ti02 12 pm tren de FTO Dac trung J-V ciia pin mat trdi dugc dilu kien AM 1.5 va dugc trinh bay tren Hinh Linh kien sir dung Rut-B cd thi mach hd {Voc) va ddng ngan mach (Jsc) cao hon so vdi Rut-Bl, cho thay hieu qua eiia chuoi hexyloxy Rut-B/DSSC cd Voc = 0.71 V, Jsc = 13.6 mA/cm^ va hi sd lip diy iff) la 0.63, cd hieu suit suat 6.1 % Trong dilu kien tuong tu, Rut-B cd Voc = 0.67 V, Jsc^ 11.5 m/KJcrx?,ff= 0.64, va cd 240 Hoi nghi Khoa hoc ky niim 35 ndm Viin KH&CNVN-Hd Noi -10-2010 hieu suit 4.87 % Hieu suit cao cua Rut-B la Rut-B cd he sd dap tit cao Chuoi hexyloxy gin tren cacbazol cho thiy kha nang tdi uu hda cau true ciia phirc ruthenium ' ' 30 ' • * V 25- X \ 10 \ \ -'•-Rut-B1 — -Rut-B 20- \ \ \ \ \ \ I 15H •o5 • — p-j -R- - -F'u • B 01 02 n ' ^-^^ \ \ \ \ \ \ \ \ \ \ \ \ 03 04 05 06 \ 5- ll 07 '—I 08 10 Oien thd (V) 20 ' 30 • 40 ' 50 ' 60 r 70 Z' (ohm) Htnh 4: Ddc trung J- V eug DSSC su dung chdt mdu Rut-Bl, Rut-B Cirdng chiiu sdng AM 1.5G (100 mW/cm') Hinh 5' Phd tdng trd diin hod cua DSSC sir dung chdt mdu Rul-B I, Rul-B Irong diiu kiin thi mgch hd, AM I.5G (100 mW/cm') Phd tdng trd dien hda (EIS) la phuong phap dap iing ddng ap dung mpt the xoay chieu la ham ciia tan sd de nghien cim ddng luc hpc ciia cac qua trinh dien hda va quang dien hda [19-21] Phd tdng trd dien hda dugc thuc hien dieu kien mach hd va md phdng anh sang mat trdi AM 1.5 (100 mW/cm") Ket qua dugc the hien bang dudng Nyquist nhu tren Hinh Zrcai (Z') va -Zjmagc (-Z") la phan thuc va phan ao ciia trd khang, dac trung cho dien trd qua trinh chuyen dien tich tao giira lien be mat va dien trd tao cd dien dung dien hda Trong hai mau DSSC, tren phd xuat hien vdng ban nguyet va tdng trd cua Rut-B/DSSC Idn han Rut-B 1/DSSC Ban nguyet d tan sd eao (>5xlO"' Hz) dac trung cho chuyen dien tich oxi hda khir d lien be mat Pt/chat dien li Ban nguyet Idn nhat d tan sd trung binh (1-5x10 Hz) dac trung cho trd khang chuyen dien tir tai lien be mat Ti02/chat mau/chat dien li va ban nguyet d viing tan sd thap (