Tgp chi khoa hgc TrUJfng Dgi hgc Quy Nhan - Sd 4, Tgp VI nSm 2012
NGHIEN ctfu PIN MAT TR^I MANG M 6 N G BANG PHlTOfNG PHAP
MO HiNH H 6 A VA M 6 P H 6 N G s dNGUvfeN DLfC HigU", VO THI THANH TUY^N'', TRAN THANH THAP 1. GI<3l T H l £ u CHUNG
Trong nghien ctJu phdt trien pin mat tr5i mang mong, phtfdng phap thiJc nghiem dtfdc su* diing rpng rai d^ nghien ctfu cdc tinh cha't vat I^ cOa vat lieu hien tai vk dong thcJi khai thdc cdc vSt lieu m<5i. Phtfdng phdp thtfc nghiem the hien nhieu utf did'm ndi trOi nhtfng n6 cung gdp phai kh6 khdn khi dieu chinh mpt thong so cong ngh6 ma khong anh htfdng nhieu den cdc thong so cong ngha khdc [1,2]. Day la van de md m6 hinh h6a va m6 phong s6' (goi t^t la m6 hlnh s6) c6 kha nang ho trd manh me. Vdi m6 hinh &6, cdc thong so rieng biet, nhtf dp rong vOng c^m, co the thay doi ma khong can thiet tac dpng cdc thong so khdc. D i l u ndy cho phep chung ta khao sat cac anh htfdng hen quan de'n m6t thong s6'md khdng dnh htfdng den cdc thong so khac. Ngoai ra, mo hinh s6' cho ph6p khao sdt cdc thong s6' cong nghe thay ddi trong mot pham vi rpng, Idn hdn ra't nhieu kha ndng thtfc hien trong phong thi nghiem. Mot thuan Idi khdc nffa cfia mo hinh so la kha ndng thie^t lap lai chinh xdc cdc thong tin nhan dtfdc ttf cdc ke't qua thtfc nghiem vd m6 phong dtfdc cac qua trinh xay ra trong thtfc nghiem. Do do, mpt kS't qua m6 phong c6 nghi ngd thi de dang xem xet tac dpng cac tham s6'dau vdo vd c6 the phat hien dtfdc cdc nguydn nhan mpt each de dang [3, 4, 5].
Ngoai nhffng ifu diem ndi trdi n6u tren, mo hinh so' cung co mpt so' nhtfdc diem.
Nhtfdc diem chinh Id khong co kha ndng xay diing mo hinh chinh xac cdc linh kien quang dien. Do do, mpi kd't qua dat dtfdc phai dtfdc xem xet trong pham vi han che cua mo hinh do. De dp dung cdc k^t qua mo phong cho cdc pin thtfc te thi can phai xdc dinh dtfdc m^i ttfdng quan giffa mo hinh ly thuyet va pin mat tr5i thtfc te [5, 6].
Trong bai bdo ndy, chiing toi thong bdo cdc ket qua nghien ctfu mo hinh hoa va mo phong so pin mat trdi mang mong tren cd sd Idp hap thu CuInS, (gpi tat la pin mat trdi CIS) bang phan m e m SCAPS-ID.
2. M O HINH S 6 PIN M A T TRCJl
Mo hinh so ciia pin mat trdi mang mong bao hdm cac bai toan so cua cdc phtfdng trinh thiet lap, chdng hinh thanh mSt m6 hinh todn cho boat dong linh kien va cdc mo hinh m6 ta cdc ddc tnffig vat lidu va cac qua tnnh boat dpng Iinh kien. Trong phan mem SCAPS-ID, cdc phtfdng tnnh cd ban dtfdc giai la phtfdng tnnh Poisson vd cdc phtfdng trinh lidn tuc doi vdi didn tuT vd l6 trong va cdc qud trinh tai hdp - phdt sinh dtfdc su" dung theo mo hlnh Shockley - Read - Hall [1 - 3].
102 NGUY6N B13C Hlfiuy VO THI THANHTUYJN*, TRAN THANHTHA^
Cic phUtfng trinh cd bin
Cic van dl v5t ly linh ki$n biin d3n diTcJc Ihi hi§n trong h$ cic phiTdng trtnh Poisson vi phUdng trinh li6n tuc di§n tOf -15 trong [1,3, 6):
E W ^ 1 = - ? [ M ^ ) - « ( X ) + A ' „ * W - W / W + P,(X)-«,(X)] (1)
^ = ? [ « W - G W ] + 9 | (2)
^'=?[;?W-G(x)]+9j (3)
Trong d6: i() 14 thfi' tinh di?n, E hSng s^ di^n m6i, n vi p U n5ng dO di$n td vi lo trd'ng tir do, N^^ vi N^ I& nong dO cdc donor vi acceptor bj ion hda, a^(\) vi p^Cx) h cdc bay dien tu' vi IS tr^ng, J^ vi J^ li mat do d6ng di^n tu' vi lo trong, R li toe do tii hop, vi G li toe do phit sinh. Trong nghien clJu niy, chi x6t bii toin mOt chilu trong che do dirng, dodo:
^ ^ = 0 vi . ^ - = 0 (4) dt dl "
Cic dieu kien tai hop trong phiTOng trinh (2) vi (3) li phu thupc khong djyen tinh vio cac nong da hat tai n vi p. He phtfOng tiinh vi phan khdng tuyen tinh (1) - (3) dildc giai bing cic phiiong phap so nhft phan mem mo phong SCAPS-ID ±eo phan bd Fermi-Dirac. Nghidm cua he bao gom ba tr^ng thii c6 th^ thay ddi i|>, F,_, vi E , nghiem niy du d^ suy ra tat ci cic die trUhg khic trong dieu kien trang thii dilfng.
Phi^tfng trinh lien tiic
Trong tnlflng hdp tdng quit, sir chuyen rSi cQa cic h?t tai didn trong bin dinbi chi phdi bdi hai qui trinh: qui trinh khu^ch tin dudi tic dung cia gradient ndng dd va qui trinh kdo theo bdi gradient didn thd' trong dien trirflng. Cic qua trinh nay diioc bieu didn bdi cic phtfdng trinh hen tuc [1, 3, 6]:
J,=1\i.n^+qD,-- (5) J,=q\i,l^-qD^^ (6) C* day: n„, p._,, D_, D^ va ^lln lUdt li dO Unh ddng cic hat tii, hkng sd khudch tin
cua cic hat tai vi tnrdng tinh dien. Vdi svf xic dinh cia cic mile quasi-Fermi, E^ va E^, va cic dien thd' quasi-Fermi, *,, = - (E„/q) va %=<B^lq), phtfdng trinh (5) vi (6) CO thd vid't rut gpn:
/.=-9H„n-J^ (7) dx
NGHIEN CCfU PIN MAT TRtil MANG MONG 103
J, = '<IV;P
dx
(8)3. CAU TRUC PIN MAT T R 6 I MANG M 6 N G VA CAC T H 6 N G S6 CO BAN DAU VAO M 6 P H 6 N G
Trong nghidn cffu niy, chung toi khdo sit pin mat trfli CIS cSfu true ddo bao gdm cic Idp vat lidu sau: ldp ci>a sd n-ZnO:In, Idp ddm n-CdS vi Idp hd'p thu p-CuInS^.
Cd'u tnic ciia pin dtfdc trinh biy nhtf trdn Hinh 1. Cic thong sd cd ban dau vao mo phong dtfdc trinh biy trong Bdng I.
+
II 1^ ]i
Anh sang mat trai
Hinh 1. Cdu true pin mat trdi CIS
Bdng 1. Cdc thdng sdcabdn ddu vdo eiia ede ldp ZnO.Tn, CdS vd CuInS^
Layer thickness (nm) Band gap (eV) Dielectric permittivity Effective density of states in conduction band (cm'^) Effective density of states in valence band (cm'')
Electron thermal velocity (cm/s) Hole thermal velocity (cm/s) Electron mobility (cmW.s) Hole mobility (cmW.s) Shallow donor density (cm') Shallow acceptor density (cm')
n-ZnO:In 250 3,3 10 2,2.10"
1,8.10"
10' 10' 100 25 1,7.10"
n-CdS 60 - 200 2,42 10 2,0.10"
1,8.10"
10' 10' 100 25 7.10"
p-CulnSj 800-3000 1,40-1,55 10 2,2.10"
1,8.10"
10' 10' 100 25 5,9.10"
NGUYEN Bl3c Hl6u-, VO THI THANH TUvfeN*, TRAN THANH THAT
4. idT QuA M 6 PH6NG VA THAO LUAN 4.1. Anh hirdng cua chilu diy ldp d^m CdS
Chidu diy Idp ddm CdS dtf(?c khdo sit trong ph^m vi S^js = 60 - 200 nm, trong khi chieu diy cdc Idp CuInS,viZnO:Indtf(?cgiOcddjnh 5„s = 2,0nmvi 5|2£, = 250nm.
Kd't qud md phdng cic thong sd quang didn ciia pin mit trdi dtf(?c th^ hi$n trong BingZ' Bang 2. Cdc thdng sd quang dlin cua pin m<ll trdi CIS md phdng bdng SCAPS-ID
khi cttiiu ddy ldp dim thay ddi
lyj Chi^u diy ldp Di$n dp hd Mit dd ddng ngin Hd sd Hidu su^t ddm (tun) mach (mV) mach (mA/cm') IJ'p ddy (%) (%) M-OI
M - 0 2 M-03 M-04 M-05 M-06 M-07 M-08
60 80 100 120 140 160 ISO 200
490 464 445 431 420 411 386 327
9,77 7,96 6,85 6,23 5,78 5,21 4,10 3,27
29,83 26,83 25,22 24,54 23,48 22,08 19,67 16,66
0,83 0,74 0,69 0,66 0,61 0,54 0,41 0,24 Hinh 2 bieu didn stf phu thu6c cdc thong so ddc tnftig ciia pin mdt trdi vdo chi^u ddy ldp d$m.
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ID eo ao 109 130 140 i«a I K 200 210 Chtfu d&y I6p d ^ (nm)
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*0 N N 100 13D 140 i n IM 300 Chlfiu djiy ldp O^m (nm) Chitu ddy Idp 0 ^ {nm}
Hinh 2. Su thay ddi (a) dien dp hd mgch (b) mat do ddng ngdn mgch, (c) h^ sdldp ddy vd (d) hi$u sudt ehuyin ddi th^^ ^
NGHlfeN g J U PIN MAT TRPI MANG MONG
Dd d i n g thd'y rJng, c i c g i i tri V^^, J^^., FF v i r| deu gidm khi 8^^^ tdng tir 60 dd'n 200 nm. Khi 5^.^^ tdng se l i m t i n g dp hS^p thu trong Idp CdS d i n dd'n l i m g i i m Itfong photon dd'n Idp hap thu va l i m giam cd V,^ va J^^ (Hlnh 2a,b). M i t khdc, stf gia tdng
"^"^ 8„s cOng lam t i n g didn trd ndi tid'p da pin m i t trdi [2,4] v i ddy cung l i nguydn nhan l i m gidm hd sd la'p day v i hidu sua't chuyen ddi (hlnh 2c,d). Ttf hinh 2 cQng c6 the nhan tha'y, cdc thdng sd d i e trtfng ciia pin m i t trdi ffng vdi chieu d i y Idp ddm
^cds = ^ "™ i^^" '^^ g'4 tri Idn nha't. Chieu day Idp dem trong dai 5^^^ = 80 - 140 nm cho thd'y pin mdt trdi v i n thu dtfcjc cdc thdng s d quang didn d i e trtfng tdi tfu vl J v i T| chi giam ddng ke khi chidu d i y 5 „ s > 140 nm.
Til kd't qua khdo sdt trdn, cho phdp chon chieu d i y CdS phil hdp u-ong pham vi 8j.^j = 6 0 - I 4 0 n m .
4.2. A n h htfdng cua chidu day ldp hS'p thv CuInSj
Chieu d i y Idp hap thu dnh htfdng rat manh de'n c i c thong sd quang didn ciia pin mdt trdi, ddc biet l i c i c pin mdt trdi trdn cd sd hd vdt lieu Cu-chalcopyrite [5,6].
Tidu chi chung nhd't tt-ong cdng nghd chd tao pin m i t trdi mang mong hidn nay l i sff dung chieu d i y Idp ha'p thu mong m i van dam bdo hieu sua't chuyen ddi quang didn cao. Ly do chinh cho stf lifa chpn n i y l i vdt lieu sff dung it v i cho phep thdi gian lang dpng nhanh. Dieu n i y ddn dd'n san phd'm pin mat trdi c6 gid thanh thd'p v i trpng Itfdng nhe hdn [5, 8].
D e x i c dinh thong sd chieu d i y tdi tfu Idp hafp thu vdi ca'u true nhtf the hien trong Ifinh 1, chung tdi khdo sdt chieu d i y Idp hd'p thu CuInS^ thay ddi trong gidi han 5^jg = 0,8 - 3,0llm, ttong khi chieu d i y ldp ZnO:In v i CdS dtfdc co dinh vdi cdc g i i tri l l n Itfdt 8 , ^ = 250 nm vd S ^ j = 120 nm.
Kd't qua md phdng cua c i c thdng so quang didn phu thudc 5^^^ dffdc trinh b i y trong Bang 3 va Hlnh 3 trinh bay dd thi quan he V^^., 1^, FF v i T] theo S(.,j.
Bdng 3. Cdc thdng sd guang dien cua pin mat trdi CIS mo phdng bdng SCAPS-ID khi chieu ddy ldp hdp thu thay ddi
„ l Chieu day ldp Didn i p hd Mdt dd dong ngdn He so Hieu suaft hap thu (|jm) mach (mV) mach (mA/cm') lap day (%) (%) M-09
M-10 M-11 M - 1 2 M-I3 M-14 M-15 M-16 M - 1 7
0,80 1,00 1,25 1,50 1,75 2,00 2,20 2,50 3,00
371 394 414 426 430 432 432 432 431
4,12 4,39 4,99 5,71 6,08 6,23 6,23 6,22 6,22
26,23 25,79 25,36 25,18 24,74 24,60 24,59 24,54 24,49
0,45 0,49 0,55 0,59 0,63 0,66 0,66 0,66 0,65
106 N0UY6N DlfC Hlfiy. VO TH[ THANH TlTyfeN'. TRAN THANH THAT Hlnh 3a,b bidu didn stf thay ddi ciia V ^ vi Jj,. theo S^j. C6 thd thay rSng, cd V^
vi Jj^ gidm ddng kd khi 8^^ < l,5nm. Khi chidu diy ldp hSfp thu mdng vilng nghdo se md rOng hdn vd phia tidp xffc mdt sau ndn lim ting si/ tii h<?p tai bd mit giffa phdn bidn ldp hd'p thu/tid'p xue mdt sau cOa pin mil (rfli ndn didn tff dd ding bi bit giff sau khi phit sinh [4, 5]. Hdn nffa, dd truydn qua ling hdn vdi Idp hd'p thu mdng ndn tdn hao quang Idn hdn. Do dd, chi mdt sd it didn tff phit sinh tham gia ddng gdp cho hieu sua't chuyen ddi ndn S^ vi V^j^ hlnh thinh c6 gii tri thd'p. Cdc If do ttdn din ddn Mdu sua't chuydn ddi suy giim khi chidu ddy ldp hdfp thu cing mdng [5].
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Chl^u ddy ldp hdp thv (am) Chidu ddy I6p hdp th^ oun) zs M
Hinh 3. Su thay ddi (a) diin dp hd mgch,(b) mat do ddng ngdn mgch, (c) hi sdldp ddy vi (d) hi$u sudt ehuyin ddi theo S
NGHISN ctfu PIN MAT TRCil M ANO M6NG 107 Mat khic, khi 5^^^> 2,0nm, gii tri V ^ vi 3^ dat gii tri bao hda. Trong ttKdng hdp niy he sd lafp diy vi hidu sua't cung gan nhff khdng ddi (FF ~ 24,6 %,r\~ 0,66 %) (xem Hinh 3c,d). Hidu sua't chuyen ddi quang didnri ciia pin mdt ttdi c6 gii tri thap trong trffdng hdp 8^,5 < 1,5 |im nhtf the hidn trong Hlnh 3d.
Nhtf vay, cdc thdng sd quang dien cua pin mdt trdi sd thay ddi khi chieu ddy cffa ldp hap thu thay ddi. Vdi tidu chi Itfa chpn nhtf ttlnh biy d tren vi dam bio stf phff hdp giffa 4 thdng sd quang didn cOa pin mdt trdi, chidu diy Idp ha'p thu Iffa chpn phil hdp nha't trong pham vi 5^^^ = 2,0 - 3,0 |tm.
4.3. Khao sdt anh hirdng cua dd rdng viing cS'm quang ldp hd'p thu
Cic kd't qua nghidn cffu ttong [9, 10] cho thd'y, do rpng vilng ca'm quang Idp hd'p thu CuInSj phu thupc ding ke vao cic thdng sd cdng nghd nhtf nhiet dp ling dpng, ti Id moi cic tidn chd't, didu kidn xff If nhidt vi qui trinh pha tap. De dat dffpc hidu sua't chuyen ddi quang dien cao ciia pin mdt ttdi, chiing ta cin khao sit dnh htfdng ddng thdi hai dai Iffdng sau [5, 6, II]:
1) Stf thay ddi dp rdng vffng ca'm ldp ha'p thu E
2) Dp lech vilng ddn AE^ tai ranh gidi chuyen tid'p CdS/CuInSj
Trong nghidn cvtu nay, chiing tdi khdo sdt E thay ddi trong khoang gii tri tff 1,40 ddn 1,55 eV. Mpt sd thdng sd cd ban dau vio sff dung trong md phdng dffdc trinh biy trong Bang 1. Bang 4 vi Hlnh 4 trinh biy kdt qud md phdng cic thdng sd quang didn ciia pin mit ttdi ttong trffdng hdp niy.
Bdng 4. Cdc ihdng so quang diin cua pin mat trdi CIS md phdng bdng SCAPS-ID khi dd r0ng vung cdm quang ldp imp thu thay dot
j^-s Dp rpng viing Didn ip hd Mat dp dong ngin He sd Hieu suaft
"" ca'm quang (eV) mach (mV) mach (mA/cm') lap day (%) (%) M-18
M-19 M-20 M-21 M-22 M-23 M-24 M-25
1,40 1,42 1,44 1,46 1,48 1,50 1,52 1,55
394 407 420 430 434 434 434 433
7,73 7,18 6,71 6,32 6,14 6,03 5,75 5,66
21,78 22,97 23,83 24,55 24,80 24,90 24,89 24,74
0,643 0,645 0,650 0,653 0,654 0,655 0,650 0,634
NGUYfeN BCfCHl6u".V0TH| THANH TUvfeN'.TRANTHANHTHAf.
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HinA 4. Su thay ddi (a) diin dp hd mgch (b) mat dg ddng ngdn mgch, (c) he sdldp ddy vd (d) hiiu sudt ehuyin ddi theo E^ cua CuInS,
Theo thdng bio ttong [11], V ^ v i E^ cd mdi quan he nhff sau:
V,
= £s-0,5(v)
(9) bie'n thi€n Trong dieu kien chieu sdng va nhiet d6 1dm viSc khSng doi, V^, tuy^n tinh vdi E^. Vi vay, khi E^ gia tdng cung 1dm gia tdng V^^,.Tren do thi Hinh 4a, cho thay V^ gia tdng tuyd'n linh khi E^ gia tdng ttf 1,40 den 1,46 eV. Sau do V^^^ gia tdng khong ddng k^ vd dat gid tri bao h6a tai gid tri N^^ - 430 mV khi E Si,48 eV. Ngu'cfc lai, J^^, suy giam khi dp rpng vCing ed'm gia tdng (xem Hinh 4b).
Nguyen nhdn hien lu'dng ndy c6 the la do khi E c6 gid tri Idn cdc photon bi hap thu tai vung p ciia pin mdt tr6j se khong du ndng Itfdng de vifdt qua vClng ca'm cda ldp hd'p thu d^ tham gia qud tnnh phat sinh cap dien tu" - lo trS^ng. Trong tnfdng hdp E = 1,5 eV thi chi cdc photon mang ndng Itfdng co gid tri hv> l,5eV se ddng gop phdt sinh cdp di€n tiJ" -16 trong vd cdc photon cd gid tri hv < 1,5 eV se bi loai tri3f.
Mpt nguyen nhan khdc c^n Irfu ;^ la khi E cd gia tri Idn se tdng ciTdng kha nang tai hdp dien lit - lo trong tai viing p trong pin mdi trdi. Do dd, cdc hat tai ttf do bi tdi hdp trtfdc khi chung khud'ch tdn dd'n viing ngheo d^ ddng gdp ddng quang dien phdt
NGHlfeNCCaiPINMAT TRdi MANG M 6 N G
sinh [2, 4 ] . C i c nguydn nhan ttdn l i m cho i^ bi suy gidm khi E gia tang. Co the thay, hidu sudt chuyen ddi I c u n g gia tdng khi E^ gia t i n g nhtfng g i i m dan sau khi dat gii tri ctfc dai (Hinh 4d). Hidu sud't ctfc dai dat dtfdc Id 11= 0,655 % tai E = l,50eV, ddy la gia tri g a n vdi g i i tri dd rdng vilng cdm tdi tfu cua ddn tinh the khd'i CuInS, ( E ^ = l , 5 3 e V ) .
Kdt hdp 4 thdng so quang dien nhdn dtfdc tff ke't qua md phdng trdn Hinh 4 cho phep chpn dd rdng vffng ed'm quang phff hdp trpng pham vi E = 1,45 - 1,50 eV.
5. KET LUAN
C i c thpng so cua pin m i l trdi m i n g mdng ZnO;In/CdS/CulnSj, bao' gdm chidu d i y Idp ddm, chieu d i y Idp hd'p Ihu v i dp rpng vffng ed'm quang Idp hd'p thu dffdc xdc dinh td'i tfu b i n g phtfdng phdp md hlnh hda v i md phdng sd sff dung AMPS-ID. Kdt qua khdo sdt cho thd'y chidu ddy Idp ha'p thu dnh hffdng manh dd'n hidu sud't chuyen ddi cua pin mat trdi CIS v i da x i c dinh pham vi Iffa chpn chieu d i y tdi ffu 2^,^ = 2,0 - 3,0 m.
Ngoii ra, chung tdi p h i t hien thay dp rpng vilng ca'm quang ldp ha'p thu khoang 1,50 eV dat hieu sua't chuyen ddi quang didn cffc dai v i xdc dinh dtfdc pham vi Iffa chon tdi tfu E^
= 1,45 - 1,50 eV. Ddi vdi Idp dem CdS, kd't qua khdo sdt cho thd'y chieu diy cd gid tti tdi tfu nhd't khodng 60 nm va xdc dinh pham vi Iffa chpn d^^ = 60 - 140 nm.
Nhtf vay, bdng phtfdng phdp md hinh hoa va md phdng sd cho phep Iffa chpn mdt sd thdng s d vdt lieu td'i tfu hd ttd hidu qua cho cdng nghd chd tao nham gidi han pham vi khdo s i t , ddng thdi lam giam dtfdc thdi gian v i chi phi thtfc nghiem.
TAI LIEU THAM KHAO
[I] AMPS-ID Manual for Windows •95/NT, The Electronic Materials and Processing Research Laboratory at the Pennsylvania State University, University Park, (2003).
[2] M. Burgelman, J. Verschraegen, B. Minnaert, J. Marlein, Proceedings of NUMOS 2007, (2007), pp.357-366.
[3] M. Gloeckler, Master Thesis, Colorado State University, (2007).
[4] T. J. Anderson, O. D. Crisalle. S. S. Li, P. H. HoIIoway, National Renewable Energy Laboratory, Golden, Colorado 80401-3393, (2003).
[5] U. Malm, Doctoral Thesis, Uppsala University, (2008).
[6] V. T. Sdn, Unh kiin bdn ddn vd vi diln ti, NXB Khoa hpc va Ky thuat, (2001).
[7] A. G. Aberle, Thin solid films 517, (2009), pp.4706-47I0.
[8J T. Markvart, L. Castaner, Solar celts: Materials, manufacture and operation, Elsevier, (2005).
[9] T. T. Thai, V. T. Son, V. T. Bich, Proc. Eleventh Vietnamese-German Seminar on Physics and Engineering, (2008), pp.227-230.
[10] T. T. Thai, V. T. Son, V. T. Bich, P. P. Hung, Proc. The Fifth National Conference on Optics and Spectroscopy, (2009), pp.425-430.
[II] M. Burgelman, J. Verschraegen, S. Degrave, P. NoIIet, Prog. Photovott: Res. Appl.
12, (2004), pp.143-153.
IIP NGUYEN DlfC Hl^U'. vO THI THANH TU vfer^. TRAN THANH THAI' SUMMARY
STUDY OF THIN FILM SOLAR CELLS
BY MODELLING AND NUMERICAL SIMULATION TECHNIQUE Nguyen Due Hieu, Vo Thi Thanh Tuyen, Tran Thanh Thai In this work, we have used one dimensional simulation program called Solar Cell Capacitance Simulator in 1 Dimension (SCAPS-ID) lo study solar cells based on CuInS^
absorber layer. Various factors affecting the solar cell's performance are investigated to obtain the optimum parameters for the ZnOiIn/CdS/CuInSj solar cells. Among the factors studied are the thickness and optical band gap of absorber layer and the thickness of buffer layer of the cells. It is found that the optimum absorber thickness is between 2.0 \itn and 3.0 \x m. Moreover, the opdmum optical band gap of the CuInSj absorber layer is found to be between 1.45 eV and 1.50 eV. The thickness of the CdS buffer layer has been found in the range of 60 nm to 140 nm as the optimum value.
•Vi§n V4t IJ ky thuSt, Tnrdng Dai Hpc Bich Khoa Hk NOi
"•Khoa H6a hoc, TrUifng Dai Hoc Quy NhcJn '^Khoa K5 thuat & C6ng ngh§, Tnfdng Dai Hpc Quy Nh(Jn Ngiy nhSn b^i: 13/02/2012; Ngiy nhSn dSng: 10/4/2012.
