Korean Chem. Eng. Res., Vol. 44, No. 2, April, 2006, pp. 179-186 vtž r v qx}v xy d dö rgö vöd Öqr *Öi i { z l, *ˆ fgywu h 561-756 { {~l 1 664-14 (2005 12x 2z {j, 2006 1x 20z ) The Preparation and Property of Dye Sensitized Solar Cells using Gil-Sung Kim, Young-Soon Kim, Hyung-Il Kim, Hyung-Kee Seo, O-Bong Yang* and Hyung-Shik Shin Thin Film Technology Laboratory, *Center for Advanced Radiation Technology, School of Chemical Engineering, Chonbuk National University, 664-14, 1 Ga, Duckjin-dong, Duckjin-gu, Jeonbuk 561-756, Korea (Received 2 December 2005; accepted 20 January 2006) t š (nanotube)v zz(nanoparticle)y { u z 450 o Cug y i {y u h y { u. z h y zw fw u u y t{ { šhy f u. zz ji u š 180 o Cug 24l s ju ˆ y n h u. z zz h y fw u {z u y t{ y u y(η)y 8.07Ûz, {s(open-circuit potential, V OC ), { (short-circuit current, I SC )v fill factor(ff) y 0.81 V, 18.29 mv/cm 2 v 66.95Ûzu. š { wu NaOH wty 3M 5M l. 3M NaOH wtug h š h y fw u {z u y t{ y u y(η)y 6.19Ûzuy, V OC, I SC v FF y 0.77 V, 12.41 mv/cm 2 v 64.49Ûzu. u 5 M NaOHug {zz hz } ss yz 4.09Û i u. u ju u y { zz { u y t{ y yz z s. q Abstract Two types of, nanotube and nanoparticle, were used for the mesoporous coatings by doctor blade technique followed by calcining at 450 o C. The coatings were used as working materials for dye-sensitized solar cells (DSCs) later on and their photovoltaic characterization was carried out. The nanoparticle was synthesized from hydrogen titanate nanotube by hydrothermal treatment at 180 o C for 24 hr. The solar energy conversion efficiency (η) of DSCs prepared by this nanoparticle reached 8.07 with V OC (open-circuit potential) of 0.81 V, I SC (short-circuit current) of 18.29 mv/cm 2, and FF (fill factor) of 66.95, respectively. For the preparation of nanotube, the concentration of NaOH solution varied from 3 M to 5 M. In the case of DSCs fabricated with nanotubes from 3 M NaOH solution, the η reached 6.19Û with V OC of 0.77 V, I SC of 12.41 mv/cm 2, and FF of 64.49Û, respectively. On the other hand, in the case of 5 M solution, the photovoltaic η was decreased with 4.09Û due to a loss of photocarriers. In conclusion, it is demonstrated that the solar energy conversion efficiency of DSCs made from nanoparticle showed best results among those under investigation. Key words: Dye-sensitized Solar Cells, Solar Energy Conversion Efficiency, Hydrothermal Treatment, Nanotube, Nanoparitcle 1. d fug fw z y u xy g u z. g u z y zy d s l vuz f { { z., 1997 u To whom correspondence should be addressed. E-mail: hsshin@chonbuk.ac.kr y{g(kyoto protocol)u y u v y l t l{ug zg u y why w ~wl z. Ÿ{z zg u tu, j u, Ÿ u, u z z. z ~ug y u {v { j z zgu xy n tu { (photovoltaic effect)u y u { u { z t{ (photovoltaic cell solar cell)z. 10Ûy yy 179
180 hù ujù zùg Ùtv Ùl l t{ { y 1Û x z w u y 10 { j z u t u z. zˆ t u z y f w u xy { hy z. t{ y uf 1839 l z Edmond Becquerel i { h hy t u l {y ty { g { (photovoltaic effect) g lz u. z u } y t{ ~ l y z w t{ 25Û y { {y y z fw z, { u y z fw, x y u { u z. zu { { j z t{ u lz z, z ~ zz zw u y t{ y ~ y z. u y t { y w 1991 O Regan Grätzel[1]u y u y u y t{ { z uy, z z y u y t{ y l t{ v y u yy l t{ { y 1/5 u s Ÿ g u y t{ f w { zy u. zˆ u y t { {, y t u { u { l ~ [2-4]. z u y t{ lw yz 20Ûz, { y { l y 5 y 1 j z, 20 y j z z, t yw hy zu, h {y y u zv u y ~{z u z. u y t{ y z x Ÿ ( y xu {, working electrode)u u z {y n- zz ( ~h y zz, working material)u t ( l g)z j u z( t jw u z, dye) {z-{ my gh, {z f y { ~z. f { y ~z {z zz y u { h ( {, counter electrode) y { u { gl. u zug gh { y f - x { (electrolyte)u y {z s l x y l y h x yw { z [5-6]. z { y t{ v {z z{y, y t{ ug tu y j { {z-{ mz u { y y {z ug lu zu u, tu y j { { z {z u tu j u, { y z y {zy ug z. z z x y u y t{ y y xu { (working electrode) u { u z zz h (working material), zz xu z y u z(dye) { (working and counter electrode) fzu z 50~100 µm y y w z f - xw { (electrolyte) wtz uz z. u y t{ u zz fw d s, Š g zw fz {, NO Agy { z ywhz t z z [7-12]. zz z {y s fz { fw u {. Li [13] y w, v wtu fz fw u h ž ž x44 x2 2006 4t {y { uy, Kambe [14]y v sy ug u wtu fz j u f(singlephase) {y h u. š y w } (high aspect ratio)u y u u { {Š y { y z z g u zz l u u y t{ y u yy fl y u z [15-17]. u y sg l ug { z titanium isopropoxide (Ti{OCH(CH 3 ) 2 } 4 y zw[18] P25 w zw[19] u s š { y u {y s { u. z y u z { u g { P25 w zw u u zz š u z z ss., ju h Š u g NaOH ˆ u sodim titanate nanotube ji u š y h u u y ~ z zw y {u u y ~ NaOHy u u w. zu, u ug 3M 5My NaOH wtug ji u š ju u y u zz h u, 450 o Cug 1l s i ˆ u š h u., zzv š h y fw u { z u y t{ y { šhy, u. 2. i 2-1. vvs žd zzv š hu P25 w (Gegussa, z) v 3 M 5 M jf š wt 0.1 M uf wt g s sj(~ph 10) z fw u. Fig. 1y zzv š y h {y u~ z. P25 w (Gegussa, z) 2g 3M 5My jf š jwt 75 mlv u 100 mly s y u 150 o Cug 48l s yl. z fw w v s y y {Š x ˆ u y yy s~ u. z ty fvug l Ž{ y j u hˆ, z Ž{ 0.5 g y l fvug 1l s 0.1 M uf wt 100 mlu {u ~u. l j hˆ zuy u ph 7z Ž{ y 60 o Cug 12l s l ji u š uy j z, 450 o C 1l s i (calcination)l y n s {fy š uy j z. ji u š 180 o Cug 24l s ju ˆ (hydrothermal treatment), h zz g s s w t(ph ~10)y ~ ˆ, z u j hˆ u l y n zz u. h y { 10 mly ju zzv š 0.5 g Šy u y u yl, z tu yuh s {hy l x ˆ { u (PEG( z : 20,000), Junsei, z ) 2 ml ˆ l ul j {. z zzv š l { h xu z y t fvug l, ~ ug 450 o Cug 30 s i l y n h y { u
Fig. 1. The synthesis steps of (a) nanoparticle and (b) nanotube.. z y y f š y X-g { g (XRD, X-ray diffraction), { ~f {z (FESEM, field-emission scanning electron microscopy), {z (TEM, transmission electron microscopy) y fw u f u. 2-2. r v qx}v xy { h y l g uuu 80Ûy y y { (ρ)z 2y ~8 Ω/cm FTO y y fw u. { h xu f { y xy Fig. 1 y y { y zzv š y h y f w u. (Ru) y i (C 58 H 86 O 8 N 8 S 2 Ru, Solaronix) y h u u t y j y{ fw u. f - x { sh š (acetonitrile)u 0.3 M LiIv 15 ml I 2 u fw u. { u {sy l x 0.2 M tert-butyl pyridine ˆ { fw uy, { u fw tÿ y Aldrich(USA)ug z u. f { (counter electrode)y ITO y xu (Pt)y u fw u. z (Pt)y {z (electron beam evaporation)u y u ~10 nm ITO glass xu u, z{(sealing agent) {uh (SX 1170-60, Solaronix) fw u. t{ { {y 2y 5mm 5mm=25mm Ÿ {y zw u y t{ y { šh 181 š v zz h y j u v (Ru) y i h u wtu 24l s u u { y u v hˆ u fvug l. z f { u y zy y, h { u 5 mm, ~60 µm {uh y hl 2~3 s y { fzy zuz v. z {u u t 100 C o y l. ITO y u z y zy y u f - x { y { ( { fzy ) ~z, y y zy l ty y y. {y x {y u {z t { y {y t 2 0.25 cm. 2-3. x}x d x { { šhy { x u { fzu {s, { (Model 2000, Keithley) (load) g u { -{s g(photocurrent-voltage curve)y { u. {{x{s (EG&G173, i šxu: EG&G M542)v lock-in amplifier fw uy xy g 150 Watty Xe(Xenon) fw u AM-1.5 f v yf y h { u. y h power analyzer(fielmaster GS, Coherent)v thermal smartsensor (LM-30V, Coherent)u y u { u. 3. 3-1. š Fig. 1(b)y y h, 150 Cug o 48l P25 jf š wtug sodium titanate š h 0.1 M HCl wt ˆ v hˆ {ug + +y Na H zv g gh. Fig. 2 3 M jf š 5 My jf š wtug h 0.1 M uf wt ˆ v i {y u, Fig. 1(b)y y uu š y XRD patternsy u~ z. š y ~ z y s {(anatase) fz u., 3 M jf š w ty { š y XRD patternz Fig. 2(a)ug z(rutile) fz z, 5 M jf š wtz Fig. 2(b) ug Žzš(brookite) fz. s { (101) zy FWHM(full-width at half-maximum) y 3M jf š ug 0.421z 5M jf š wtug 0.589 5M jf š wtug { š y. x z P25 zz {hy z š {hz z s. g 3 M NaOH š h u y z {hz [20-22] yf. Fig. 2y XRD šhy š zw u z y { h y SEM micrograph Fig. 3u u. Fig. 3(a), (b)v (e) 3 M jf š wtug h š y fw u {z h y Ÿ y Fig. 3(a)ug y u jl µmz y z z y j zy, Fig. 3(a) Fig. 3(b)ug zzy 20~30 nmz x y zz h uyy z j z., Fig. 3(a), (b)y z Fig. 3(e)ug Ÿ z uz z y z j z. 5 M jf š Korean Chem. Eng. Res., Vol. 44, No. 2, April, 2006
182 hù ujù zùg Ùtv Ùl l Fig. 2. XRD patterns of nanotubular materials treated with 0.1 M HCl solution and calcined at 450 o C for 1 hr, which is obtained from sodium titanate nanotube synthesized at different concentration of NaOH solution at 150 o C for 48 hr: (a) 3 M NaOH, (b) 5M NaOH ( Anatase, Rutile and brookite). wtug h š y fw u {z h y Ÿ z Fig. 3(c)ug uz z sy zz y y z { zu y z j z. Fig. 3(d)ug 10~20 nm x y zz 10~20 nmz š v, š xu h u z y z j z. u z sgg u u [19, 23] 10 M NaOH zw u { w h FESEM TEM y f š y y t 10 nm, z t 200 nm z Fig. 3(d)v yf s š zy z j zu. Fig. 3(f)ug uz z s y j zy 3M j f š wtug h (Fig. 3(e)) w Ÿ zy z j z. Fig. 3y u jf š wty ji u š y h {hu u y ~ 5M jf š wtug š h y g. Fig. 3y š h y zw { u y Fig. 3. FE-SEM images of various films prepared by nanotubular (anatase) materials. 3 M NaOH(a, b) and 5 M NaOH (c, d). Cross-section images of 3 M NaOH(e) and 5 M NaOH(f). ž ž x44 x2 2006 4t
zw u y t{ y { šh 183 Fig. 4. I-V curves of two types films prepared by anatase phase nanotubular materials at 3 M NaOH and 5 M NaOH solution. t{ y { -{s šhy Fig. 4ug jf š wty u u~ z. 3 M 5 M jf š wty { t{ y {s(v OC )y 0.77 Vv 0.82 Vz, { (I SC ) 12.41 ma/cm 2 v 7.25 ma/cm 2 zy u~. Fig. 4 { -{s gy u Fig. 5u u. 3 M 5 M jf š wty { t{ y { (P m )y 5.7 mwv 4 mwz z {s(v m ) { (I m ) y 0.55 V, 10.3 ma/cm 2 z 0.67 V, 6.1 ma/cm 2 z. { z 3 M NaOH ug { š ug zy zz fzy {zz hz š } z y g. Fig. 4 5ug u y t{ y { šhy Table 1ug u~ z. jf š wty 3 Mug 5 M u g { y V OC 0.77 Vug 0.82 V. tu { yy jf š wty 3Mug 5M u g 6.19Ûug 4.09Û i Fig. 5. Power-V curves of two types films prepared by anantase phase nanotubular materials at 3 M NaOH and 5 M NaOH solution. Table 1. Photovoltatic performance of DSCs fabrication with 3 M, 5 M NaOH concentration and Ru-dye Conditions V OC (V) I SC (ma/cm 2 ) FF ( ) η ( ) 3 M, 450 o C 0.77 12.41 64.49 6.19 5 M, 450 o C 0.82 7.25 68.69 4.09. z xy P m y y t{ y { z u {zz hz i u tu { yu zs y f. 3-2. vv Fig. 6y ji u š { u ju u y h Fig. 1(a)y y { zzy SEM TEM micrograph u ~ z. Fig. 6(a) Fig. 3(b)v Fig. 6. (a) FE-SEM images, (b) TEM image of nanotubular (anatase) particles synthesized hydrothermal treatment with 0.1 M HCl solution at 180 o C for 24 hr. Korean Chem. Eng. Res., Vol. 44, No. 2, April, 2006
184 hù ujù zùg Ùtv Ùl l z x y zzz Fig. 3(b) h y zz u y z. Fig. 6(b) u ~10 nmz zzy g ly j z. Fig. 7 Fig. 6ug uu, ju ˆ u y uu zz z 450 o Cug 30 y i ˆ y n {z h y XRD SEM f y u ~ z. Fig. 7(a) { h z FTO y y XRD z. i sy l z Fig. 7(c)ug Žz š f z fz 450 o Cugy i {y h zzz Fig. 7(b)ug f Žzš fz z y s { f z y z j z., Fig. 7(d) y i {y u { h y Ÿ u s Fig. 5(a) v uz uyy u ~ u{ zzy y fy z j z. Fig. 7(e)y SEM f y uz u y j z. Fig. 8y s { fz zz { h y {, { -{s g { -{s gy u ~ z. z i {u y {z s { fy zz h y V OC v I SC 0.81 Vv 18.29 mv/cm 2 y., P m y 7.87 mwz z V m I m y 0.52 V, 16.0 ma/cm 2., FFv tu { y (η)y 66.95Ûv 8.07Û y. 4. u ug zw g s š v zz f w u u y t{ {z u. š v zz { {ug NaOH wty 3 M NaOH 5M NaOH l y, z uu s { fz z 450 o Cy i {y zw u h y { u. z h y fw u {z u y t{ y { { šhy { u. 3M jf š ug h š h y fw u y t{ y V OC, I SC y 0.77Vv 12.41 mv/cm 2 y., FFv tu { y(η)y 66.49Ûv 6.19Û y. u 5M jf š ug h š h y fw u y t{ y w w zy iv š h FTO y {Š z i u { { šhz i. u ug fw zw y z (anatase) zz ji u š { fw u ju Fig. 7. XRD patterns and FE-SEM images of fims prepared by nanostructured (anatase) paricles synthesized hydrothermal treatment with 0.1 M HCl solution at 180 o C for 24 hr as a function of calcination temperature. XRD patterns (a) FTO glass, (b) nanoparticle calcined at 450 o C for 1 hr, (c) mesoporus coating of room temperature, (d) Cross-section image (e,f) Surface image of nanoparticle calcined at 450 o C for 1 hr, ( Anatase, brookite, and PEG) ž ž x44 x2 2006 4t
zw u y t{ y { šh 185 Ÿ Fig. 8. (a) Photocurrent, (b) I-V curve, (c) Power-V curve of film prepared by nanostructured fims prepared by nanostructured (anatase) paricles synthesized hydrothermal treatment with 0.1 M HCl solution at 180 o C for 24 hr and calcination at 450 o C. u y h u. z (anatase) zz h y fw u {z u y t{ y V OC, I SC, FF, tu { y(η)y 0.81 V, 18.29 mv/cm 2 66.95Ûv 8.07Ûy y. z (anatase) zz (anatase) š u u y t{ ywu y zz y z fly s j z. 1. O Regan, B. and Grätzel, M., A Low-cost, High-efficiency Solar Cell Based on Dye-sensitized Fimls, Nature, 353, 737-740(1991). 2. Grtzel, M., Photoelectrochemical Cells, Nature, 414, 338(2001). 3. Hara, K., Tachibana, Y., Ohga, Y., Shinpo, A., Suga, S., Sayama, K., Sugihara, H. and Arakawa, H., Dye-sensitized Nanocrystalline Solar Cells Based on Novel Coumarin Dyes, Solar Energy Materials and Solar Cells, 77(1), 89(2003). 4. Qiu, F. L., Fisher, A. C. and Walker, A. B., The Distribution of Photoinjected Electrons a Dye-sensitized Nanocrystalline Solar Cell Modelled by a Boundary Element Method, Electrochemistry Communications, 5(8), 711-716(2003). 5. Nguyen, T.-V., Lee, H.-C. and Yang, O-B., The Effect of Prethermal Treatment of Nano-particles on the Performances of Dye-sensitized Solar Cells, Solar Energy Materials and Solar Cells, In Press, Corrected Proof, Available online 11 July(2005). 6. Park, N. G., Dye-sensitized Solar Cell, J. Korean Ind. Eng. Chem., 15(3), 268(2004). 7. Kim, K. Y., Lee, K. Y., Kwon, O. K., Shin, D. M., Sohn, B. C. and Choi, J. H., Size Dependence of Electroluminescence of Nanoparticle (rutile- ) Dispersed MEH-PPV Films, Synthetic Metals, 110-112, 207-211(2000). 8. Houzouil, T., Saito, N., Kudo, A. and Sakata, T., Electroluminescence of Film and :Cu 2+ Film Prepared by the Sol-gel Method, Chemical Physics Letters, 254(1-2), 109-113(1996). 9. Na, Y. S., Song, S. K. and Park, Y. S., Photocatalytic Decoloriation of Rhodamine B by Immobilized /UV in a Fluidizedbed Reactor, Korean J. Chem. Eng., 22(2). 196-200(2005). 10. Nam, W. S. and Han, G. Y., A Photocatalytic Performance of Photocatalyst Prepared by the Hydrothermal Method, Korean J. Chem. Eng., 20(1), 180-184(2003). 11. Lee, Y. G., Lee, T. G. and Kim, W. S., Comparison of the Mercury Removal Efficiency Using Powder under Various Light Source, Korean Chem. Eng. Res., 43(1), 170-175 (2005). 12. Kwon, T. R., Roo, W. H., Lee, C. W. and Lee, W. M., Preparation of Wall Paper Cated with Modified and their Photocatalytic Effects for Removal of No in Air, Korean Chem. Eng. Res., 43(1), 1-8(2005). 13. Li, Y., Hagen, J., Schaffrath, W., Otschik, P. and Haarer, D., Titanium Dioxide Films for Photovaltaic Cells Derived from a Solgel Process, Solar Energy Materials and Solar Cells, 56(2), 167-174(1998). 14. Kambe, S., Murakoshi, K., Kiramura, T., Wada, Y., Yanagida, S., Komiriami, H. and Kera, Y., Mesoporous Electrodes having tight Aqqlomeration of Single-phase Anatase Nanocrystallites: Application to Dye-sensitized Solar Cells, Solar Energy Materials and Solar Cells, 61(4), 427-441(2000). 15. Uchida, S., Chiba, R., Tomiha, M., Masaki, N. and Shirai, M., Application of Titania Nanotubes to a Dye-sensitized Solar Cell, Electrochemistry, 70(6), 418(2002). 16. Kasuga, T., Hiramatsu, M., Hoson, A., Sekino, T. and Nihara, K., Formation of Titanium Oxide Nanotube, Langmuir, 14, 3160(1998). 17. Kasuga, T., Hiramatsu, M., Hoson, A., Sekino, T. and Nihara, K., Titania Nanotubes Prepared by Chemical Processing, Advanced Materials, 11(15), 1308(1999). Korean Chem. Eng. Res., Vol. 44, No. 2, April, 2006
186 hù ujù zùg Ùtv Ùl l 18. Godbole, V. P., Kim, G. S., Dar, M. A., Kim, Y. S., Seo, H. K., Khang, G. and Shin, H. S., Hot Filament Chemical Vapor Deposition Processing of Titanate Nanotube Coatings, Nanotechnology, 16(8), 1186(2005). 19. Godbole, V. P., Kim, Y. S., Kim, G. S., Dar, M. A. and Shin, H. S., Synthesis of Titanate Nanotubes and Its Procesing by Different Methods, Electrochimica Acta(in accepted). 20. Seo, D. S., Lee, J. K. and Kim, H., Preparation of Nanotubeshaped Powder, Journal of Crystal Growth, 229, 428-432 (2001). 21. Seo, D. S., Lee, J. K., Lee, E. G. and Kim, H., Effect of Aging Agents on the Formation of Nanocrystalline Powder, Materials Letters, 51, 115-119(2001). 22. Chen, Y. F., Lee, C. Y., Yeng, M. Y. and Chin, H. T., Preparing titanium Oxide with Various Morphologies, Materials Chemistry and Physics, 81, 39-44(2003). 23. Kim, G. S., Godbole, V. P., Kim, Y. S., Seo, H. K. and Shin, H. S., Sodium Removal from Titanate Nanotubes in Electrodeposition Process, Electrochemistry Communications(in accepted). ž ž x44 x2 2006 4t