Bộ giáo dục đào tạo Trờng đại học bách khoa hà nội - O C TUN NGHIấN CU CH TO V MT S TNH CHT VT Lí CA CC LP MNG BN DN H THIC SUNPHUA (p-SnS), (n-SnS2), (n-Sn2S3) NH HNG NG DNG TRONG PIN MT TRI TH H TH MI THN THIN VI MễI TRNG Luận văn thạc sỹ khoa học Ngời hớng dẫn khoa học ts Phỳc Hi Hà Nội- 2011 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng MC LC DANH MC CC BNG DANH MC CC HèNH V M U CHNG 1: TNG QUAN 10 1.1 Pin Mt tri 10 1.1.1 Nguyờn tc hot ng ca pin Mt tri 10 1.1.2 Hiu sut ca pin Mt tri 11 1.1.3 S phỏt trin ca pin Mt tri 22 1.2 Mng bỏn dn h thic sunphua (p-SnS, n-SnS2 v n-Sn2S3) 28 1.2.1 Mng SnS 28 1.2.1.1 c im hỡnh thỏi, cu trỳc ca mng SnS 28 1.2.1.2 Tớnh cht quang ca mng SnS 31 1.2.1.3 Tớnh cht in ca mng SnS .33 1.2.2 Mng SnS2 v Sn2S3 34 1.2.2.1 c im hỡnh thỏi, cu trỳc ca mng SnS2 v Sn2S3 .34 1.2.2.2 Tớnh cht quang ca mng SnS2 v Sn2S3 37 1.2.2.3 Tớnh cht in ca mng SnS2 v Sn2S3 .39 CHNG 2: THC NGHIM .41 2.1 Thc nghim ch to cỏc mng thic sunphua 41 2.1.1 H phun nhit phõn 41 2.1.2 Quy trỡnh ch to cỏc mng thic sunphua trờn h phun nhit phõn 43 2.2 Cỏc phng phỏp kho sỏt mng 44 2.2.1 Phng phỏp hin vi in t quột (SEM) 44 2.2.2 Phng phỏp ph tỏn sc nng lng tia X (EDAX) .45 2.2.3 Phng phỏp UV-Vis 46 2.2.4 Phng phỏp o hiu ng Hall 47 CHNG 3: KT QU V THO LUN 51 3.1 Nghiờn cu ch to mng thic sunphua (SnS, SnS2 v Sn2S3) bng phng phỏp phun nhit phõn 51 3.2 Tớnh cht Vt lý ca mng SnS .58 Hc viờn: o c Tuõn Khúa : 2009 2011 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng 3.2.1 Tớnh cht Vt lý ca mng SnS khụng pha 58 3.2.2 Tớnh cht Vt lý ca mng Sn1-xCuxS (x =0, 0,10 v 0,15) 63 3.3 Tớnh cht Vt lý ca mng SnS2 73 3.4 Tớnh cht Vt lý ca mng Sn2S3 77 KT LUN .81 HNG NGHIấN CU TIP THEO CA LUN VN 84 TI LIU THAM KHO 85 Hc viờn: o c Tuõn Khúa : 2009 2011 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng DANH MC CC BNG Bng III.1: Kt qu phõn tớch thnh phn ca mt s mng thic sunphua .56 Bng III.2: Thụng s cụng ngh ch to cỏc mng thic sunphua 57 Bng III.3: Thnh phn cỏc nguyờn t mng SnS trc v sau .62 Bng III.4: Kt qu phõn tớch ph tỏn sc nng lng ca mng Sn1-xCuxS 64 Bng III.5: B rng nng lng vựng cm Eg ca cỏc mng Sn1-xCuxS 71 Bng III.6: Kt qu phõn tớch thnh phn cỏc mng Sn1-xCuxS trc v sau 71 Bng III.7: Kt qu phõn tớch hiu ng Hall bng phng phỏp Van Der Pauw 72 ca mng Sn0.90Cu0.10S 72 Bng III.8: Giỏ tr b dy v b rng nng lng vựng cm Eg ca 77 cỏc mng SnS2, CdS v In2S3 77 Hc viờn: o c Tuõn Khúa : 2009 2011 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng DANH MC CC HèNH V Hỡnh I.1: Cu to mt pin Mt tri n gin 10 Hỡnh I.2: Cu trỳc vựng nng lng ti T > 0K ca bỏn dn vựng cm trc tip (a) v giỏn tip (b) .12 Hỡnh I.3: Quỏ trỡnh hp th photon cú nng lng h = E2 E1> Eg bỏn dn vựng cm trc tip 13 Hỡnh I.4: Quỏ trỡnh hp th photon bỏn dn vựng cm giỏn tip vi photon ti cú nng lng hv < E2 E1 v photon ti cú nng lng hv > E2 E1 14 Hỡnh I.5: Cỏc quỏ trỡnh tỏi hp cht bỏn dn 16 Hỡnh I.6: Cỏc trng thỏi b mt ti b mt ca cht bỏn dn hoc mt phõn cỏch gia hai vt liu khỏc 18 Hỡnh I.7: c trng I-V ca pin Mt tri 21 Hỡnh I.8: Th h pin Mt tri th nht da trờn tinh th Si .23 Hỡnh I.9: Pin Mt tri th h th 24 Hỡnh I.10: S cu trỳc pin Mt tri da trờn hp cht bỏn dn CIGS 26 Hỡnh I.11: Pin Mt tri da trờn vt liu hu c 28 Hỡnh I.12: Cu trỳc ca mng SnS 29 Hỡnh I.13: Gin nhiu x tia X ca mng SnS ch to bng .29 phng phỏp phun nhit phõn .29 Hỡnh I.14: nh SEM chp b mt cỏc mng SnS ch to bng phng phỏp phun nhit phõn ti cỏc nng dung dch a) 0,03M v b) 0,1 M [38] 30 Hỡnh I.15: S thay i ca t l Sn/S theo nng dung dch [38] 31 Hỡnh I.16: Ph truyn qua ca mng SnS ch to bng 31 phng phỏp phun nhit phõn .31 Hỡnh I.17: S bin thiờn ca nng lng vựng cm theo nhit ca mng SnS ch to bng phng phỏp phun nhit phõn 32 Hỡnh I.18: S thay i ca linh ng Hall v mt ht ti theo nhit .34 Hỡnh I.19: Cu trỳc mng SnS2 35 Hỡnh I.20: Gin nhiu x tia X ca mng SnS2 ch to bng phng phỏp núng chy [49] 35 Hỡnh I.21: Gin nhiu x tia X ca mng Sn2S3 ch to bng phng phỏp phun nhit phõn .36 Hc viờn: o c Tuõn Khúa : 2009 2011 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng Hỡnh I.22: Ph truyn qua T v phn x R ca mng Sn2S3 ch to bng phng phỏp phun nhit phõn 37 Hỡnh I.23: Ph truyn qua T ca mng SnS2 ch to bng phng phỏp phun nhit phõn [31] 38 Hỡnh I.24: th biu din (h)2 ph thuc vo h [27] 38 Hỡnh I.25: th biu din log theo 1000/T ca mng SnS2 [43] 40 Hỡnh II.1: S mụ t h phun nhit phõn 42 Hỡnh II 2: Cỏc tớn hiu v súng in t phỏt t mu o 45 Hỡnh II.3: S nguyờn lý h o UV-Vis hai chựm tia .47 Hỡnh II.4: S nguyờn tc phộp o hiu ng Hall 48 Hỡnh II.5: Cỏc cỏch thit lp cho mu o hiu ng Hall 49 Hỡnh III.1: Quỏ trỡnh hỡnh thnh mng bng phng phỏp phun nhit phõn .52 Hỡnh III.2: Cỏc kh nng hỡnh thnh ht vi cỏc hỡnh thỏi khỏc 53 phng phỏp phun nhit phõn [9] 53 Hỡnh III.3: Quỏ trỡnh kt tinh ca cht to mng t git dung dch cha tin cht phng phỏp phun nhit phõn [29] .53 Hỡnh III.4: Hỡnh thỏi b mt cỏc mng thic sunphua c ch to ti cỏc iu kin cụng ngh khỏc .55 Hỡnh III.5: Ph tỏn sc nng lng EDS ca mng SnS .56 Hỡnh III.6: nh mapping mụ t s phõn b cỏc nguyờn t ca mng SnS 57 Hỡnh III.7: nh AFM chp b mt mng SnS sau ch to .58 Hỡnh III.8: H s hp th ca mng SnS sau ch to 59 Hỡnh III.9: H s hp th ca mng SnS sau t = 0, v 4h 60 Hỡnh III.10: th (h)2ph thuc vo h ca mng SnS 61 Hỡnh III.11: th (h)2ph thuc vo h ca mng SnS sau 61 Hỡnh III.12: nh SEM b mt cỏc mng a) Sn0.95Cu0.05S, b) Sn0.90Cu0.10S v c) Sn0.85Cu0.15S c lng ng bng phng phỏp phun nhit phõn .63 Hỡnh III.13: nh AFM chp b mt mng Sn0.90Cu0.10S 63 Hỡnh III.14: Ph tỏn sc nng lng EDS ca mng Sn0.90Cu0.10S .64 Hỡnh III.15: nh mapping b mt mng Sn0.90Cu0.10S 65 Hỡnh III.16: Ph hp th ca cỏc mng Sn1-xCuxS theo h .65 Hỡnh III.17: th (h)2 ph thuc vo h ca mng Sn1-xCuxS .66 Hỡnh III.18: Ph hp th ca cỏc mng Sn1-xCuxS sau 2h ti 200 oC 67 Hc viờn: o c Tuõn Khúa : 2009 2011 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng Hỡnh III.19: Ph hp th ca mng Sn0.90Cu0.10S sau 2h 67 Hỡnh III.20: Ph hp th ca mng Sn0.95Cu0.05S trc , 2h v 4h 68 Hỡnh III.21: Ph hp th ca mng Sn0.90Cu0.10S khụng , 2h v 4h 68 Hỡnh III.22: Ph hp th ca mng Sn0.85Cu0.15S khụng , 2h v 4h 69 Hỡnh III.23: th (h)2 ph thuc vo h ca mng Sn0.95Cu 0.05S 69 Hỡnh III.24: th (h)2 ph thuc vo h ca mng Sn0.90Cu 0.10S 70 Hỡnh III.25: th (h)2 ph thuc vo h ca mng Sn0.85Cu 0.15S 70 Hỡnh III.26: nh SEM v ph tỏn sc nng lng EDS ca mng SnS2 .73 Hỡnh III.27: nh mapping th hin s phõn b ca cỏc nguyờn t mng SnS2 .74 Hỡnh III.28: Ph truyn qua v b dy ca mng SnS2 .74 Hỡnh III.29: nh FESEM v ph tỏn sc nng lng EDS ca mng CdS 75 Hỡnh III.30: nh AFM v ph tỏn sc nng lng EDS ca mng In2S3 75 Hỡnh III.31: Ph truyn qua ca cỏc mng SnS2, CdS v In2S3 theo bc súng 76 Hỡnh III.32: th (h)2 ph thuc vo h ca cỏc mng SnS2,CdS v In2S3 77 Hỡnh III.33: nh SEM v ph tỏn sc nng lng EDS ca mng Sn2S3 78 Hỡnh III.34: nh mapping th hin s phõn b cỏc nguyờn t mng Sn2S3 79 Hỡnh III.35: Ph truyn qua ca mng Sn2S3 theo bc súng .79 Hỡnh III.36: th (h)2 ph thuc vo h ca mng Sn2S3 80 Hc viờn: o c Tuõn Khúa : 2009 2011 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng M U Trong xó hi ngy nay, m nn kinh t cng phỏt trin thỡ cuc sng ca ngi tng h gia ỡnh cng b l thuc vo cỏc thit b in nh mỏy tớnh, iu hũa, t lnh hay bỡnh núng lnh, Trỏi ngc vi s phỏt trin ú cỏc ngun nng lng húa thch m chỳng ta ó s dng t lõu nh than ỏ, du m ang ngy cng cn kit v thm c ngun nng lng t giú, t nc (c bit n l ti nguyờn vụ tn) nh thy in, thy triu dự ó hot ng ht cụng sut cú th cng khụng kh nng ỏp ng nhu cu in ca xó hi hin Khụng ch vy, thnh phn ca than ỏ v du m cú cha rt nhiu cacbon m chỏy to cacbon oxit, õy c coi l nguyờn nhõn chớnh gõy lờn hin tng núng dn lờn ca Trỏi t v cũn gõy ụ nhim mụi trng gii bi toỏn nng lng ny, nhiu ngun nng lng sch nh nng lng Mt tri, nng lng ht nhõn, nng lng a nhit, ó c nghiờn cu ng dng vo thc t Nng lng ht nhõn cú cụng sut ln nht v c coi gn nh phi cacbon Hin ngun nng lng ny chim ti 20 % in nng m chỳng ta s dng Tuy nhiờn, kh nng ụ nhim, gõy nguy him n ngi xy s c ht nhõn l rt nghiờm trng, cha k vic x lý rỏc thi ht nhõn cng ang l mt bi toỏn phc v tn kộm Hn na, chi phớ xõy dng v bo trỡ nh mỏy nng lng ht nhõn l rt ln v ang ngy cng tng lờn Trong ú, nng lng Mt tri l ngun nng lng t nhiờn cú tr lng di li cha c khai thỏc trit Nng lng Mt tri c sn sinh ch yu l cỏc phn ng ht nhõn bờn lũng nú phỏt v theo tớnh toỏn thỡ quỏ trỡnh ny s cũn kộo di khong t nm na, vỡ vy cú th núi nng lng Mt tri l mt ngun nng lng vụ tn Theo thng kờ mi giõy Mt tri bc x xung b mt Trỏi t mt lng nng lng rt ln c 17,57.1016 J hay tng ng nng lng sinh t chỏy triu tn than ỏ Mc dự vy, chỳng ta mi ch s dng c mt phn rt nh tng s lng nng lng khng l núi trờn Thờm vo ú cỏc chuyờn gia v nng lng tỏi to cho bit vũng vi nm gn õy, chi phớ sn xut cỏc tm thu nng lng Mt tri ó gim Hc viờn: o c Tuõn Khúa : 2009 2011 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng khong 50-70 % Jigar Shah, ch mt cụng ty kinh doanh nng lng Mt tri ng thi l giỏm c iu hnh t chc Carbon War Room cho bit: "Vi cỏc tm pin quang nng, Trung Quc ang lm iu m h ó lm tng t vi mỏy tớnh v in thoi iPhone - ú l gim giỏ thnh" Cỏc thit b pin Mt tri hin c ch to da trờn cỏc cht bỏn dn nh Si, GaAs, CdTe, CIS (Copper Indium Diselenide) v CIGS (Copper Indium Gallium Diselenide) ó cho hiu sut quỏ trỡnh chuyn i bc x Mt tri thnh in nng cao nhng s khan him, giỏ thnh cao (In, Ga) hay c hi (Cd, Se) m nghiờn cu tỡm kim cỏc vt liu mi cú h s hp th > 104 cm-1, r tin, thõn thin vi mụi trng ang c tip tc trin khai H vt liu thic sunphua (SnS, SnS2 v Sn2S3) c to nờn t cỏc nguyờn t Sn v S khụng c hi, cú tr lng di t nhiờn v cỏc quỏ trỡnh x lý chỳng thõn thin vi mụi trng Trong h vt liu thic sunphua, SnS cú h s hp th > 104 cm-1v Eg = 1,3 eV thớch hp lm lp hp th pin Mt tri, SnS2 cú h s truyn qua cao v b rng vựng cm rng lờn ti 3,0 eV rt thớch hp lm lp truyn qua pin Mt tri Bi vyNghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng l mt ti khoa hc cú tớnh thc tin cao v ó c chn lm ti ca lun thc s ny Mc tiờu ca lun l nghiờn cu ch to cỏc mng bỏn dn h thic sunphua bng phng phỏp phun nhit phõn, phõn tớch mt s tớnh cht vt lý ca cỏc mng ó ch to bng cỏc phng phỏp nh SEM, AFM, EDS, ph hp th v truyn qua UV-Vis, hiu ng Hall Vi mc tiờu ú, lun c trỡnh by bao gm cỏc phn chớnh nh sau: M u Chng 1- Tng quan Trỡnh by v c s vt lý ca pin Mt tri Tng quan v vt liu hp th v cỏc th h pin Mt tri Tng quan v h vt liu thic sunphua (SnS, SnS2 v Sn2S3) Hc viờn: o c Tuõn Khúa : 2009 2011 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng Chng 2- Thc nghim Trỡnh by chi tit v phng phỏp phun nhit phõn v thc nghim ch to mng bng phun nhit phõn Cỏc phng phỏp phõn tớch tớnh cht Vt lý ca mng Chng 3- Kt qu v tho lun Chng ny trỡnh by cỏc kt qu nghiờn cu ch to v tớnh cht Vt lý ca mng SnS, SnS2 v Sn2S3 bng phng phỏp phun nhit phõn Bờn cnh ú, cỏc kt lun v s thay i ca h s hp th v b rng nng lng vựng cm Eg kho sỏt s pha Cu vo mng SnS cng c trỡnh by Ngoi ra, cỏc kt qu so sỏnh tớnh cht quang gia cỏc mng SnS2, CdS v In2S3 c ch to bng phng phỏp phun nhit phõn nhm tỡm kim kh nng thay th ca SnS2 cho cỏc mng CdS c hi hay In2S3 t cỏc ng dng ca pin Mt tri cng nh cỏc thit b quang in t khỏc cng c a chng ny Kt lun Ti liu tham kho Hc viờn: o c Tuõn Khúa : 2009 2011 Nghiờn cu ch N c to v mt m s tớnh cht Vt lýý ca cỏc l p mng bỏnn dn h thhic suunphua (p-S SnS, n-SnS2, n-Sn2S3) nh hngg ng dng pin Mt M tri th h t mi thhõn thin v th i mụi trnng Hỡnh IIII.31 biu din d truyyn qua caa cỏc mngg SnS2, CdS S v In2S3 c ch to bng phng p phỏỏp phun nhit phõn theo bc súng T kt qu so sỏnnh truynn qua trờn hỡnh h III.31, ta thy mng SnS2 cúú kh nn ng cho truyn qua cao tng ng vi mn ng In2S3 vựng b c súng t 550 ữ 1100 nm kh hi ch to bi b cựng mt phng phỏp p phun nhit phõnn Tuy nhiờnn, cú s di chuyn ca b hpp th quangg hc ca mng m SnS2 v phớa b c súng ngn n Mng CdS cú truyn qua cao nht nhng l mng mnng nht vi dy 1000 nm v cú s m rng ca ng truynn qua v phớớa bc súnng ngn rnng nht B rng ng nng l ng vựng cm Eg ca ccỏc mng cúú th c xxỏc nh t kt qu oo ph nn truy yn qua v b dy caa cỏc mng sau tớn nh toỏn v biu b din cỏỏc giỏ tr ( h)2 theeo giỏ tr nnng lng phhoton ỏnh ssỏng h (hỡn nh III.32) 100 SnS 80 CdS In S T (%) 60 40 20 300 400 500 600 700 800 9000 1000 11100 Bớc sóng (nm) H Hỡnh III.31:: Ph truynn qua ca cỏc c mng SnnS2, CdS v In2S3 theo bc súngg H c viờn: oo c Tuõnn Khúaa : 2009 2011 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng 500 SnS2 CdS In2S3 (h)2 (104 cm-1.eV)2 400 300 200 100 0 h (eV) Hỡnh III.32: th (h)2 ph thuc vo h ca cỏc mng SnS2,CdS v In2S3 Giỏ tr b rng nng lng vựng cm Eg ca cỏc mng SnS2, CdS v In2S3 c tng kt li nh bng III.9 Kt qu tớnh toỏn bng cho thy mng SnS2 cú giỏ tr b rng nng lng vựng cm Eg = 3,0 eV, giỏ tr ny ln hn cỏc giỏ tr c cụng b cỏc ti liu khỏc (Eg = 2,35 ữ 2,65 eV) S khỏc bit ny cú th c gii thớch l thnh phn mng to cha Cl d Bng III.8: Giỏ tr b dy v b rng nng lng vựng cm Eg ca cỏc mng SnS2, CdS v In2S3 Tờn mu B dy (nm) B rng nng lng vựng cm Eg (eV) SnS2 370 CdS 100 2,35 In2S3 350 2,96 Do vy xột v phng din tớnh cht quang hc ó kho sỏt, yu t giỏ thnh v s thõn thin vi mụi trng, mng SnS2 hon ton l ng c tim nng thay th mng CdS v In2S3 cỏc ng dng ch to pin Mt tri cng nh kh nng ng dng cỏc thit b quang in t khỏc 3.4 Tớnh cht Vt lý ca mng Sn2S3 Hc viờn: o c Tuõn Khúa : 2009 2011 77 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng Trong cỏc vt liu thic sunphua (SnS, SnS2 v Sn2S3) Sn2S3 l vt liu ớt c quan tõm hn so vi SnS v SnS2 Vt liu SnS vi kh nng hp th ỏnh sỏng mnh cú th c dựng lm lp hp th pin Mt tri, SnS2 vi kh nng cho truyn qua ti 80 % ỏnh sỏng vựng kh kin cú th ng dng thay th cho cỏc vt liu CdS c hi hay In2S3 t dựng lm lp ca s pin Mt tri Tuy nhiờn, nu s dng SnS lm vt liu hp th loi p cũn SnS2 lm lp ca s loi n thỡ ti b mt chuyn tip p-n ny khụng th trỏnh vic hỡnh thnh lp mng Sn2S3 (c cho l tng hp ca SnS2 v SnS) Hn th na, nh ó trỡnh by phn trờn quỏ trỡnh ch to mng SnS cú th cú s hỡnh thnh pha Sn2S3 trung gian cỏc iu kin khụng ti u Do ú, vic nghiờn cu ỏnh giỏ tớnh cht ca mng Sn2S3 l cn thit Mng Sn2S3 ó c ch to bng phng phỏp phun nhit phõn ti nhit TS = 300 oC, nng CM = 0,20 M v tc phun v = ml/phỳt Kt qu phõn tớch b mt v thnh phn cho thy mng Sn2S3 cú b mt mn, ng nht bỏm dớnh tt v t t l Sn/(S+Cl) = 0,71 gn ỳng t l hp thc (Sn/(S+Cl) = 0,67) nh biu din trờn hỡnh III.33 Thụng thng, thnh phn ca mng thiu ht S ng ngha mng cú nhng khuyt trng ca S v mng th hin tớnh cht ca bỏn dn loi n Cl 10.99% Sn 41.51% S 47.49% Hỡnh III.33: nh SEM v ph tỏn sc nng lng EDS ca mng Sn2S3 Hc viờn: o c Tuõn Khúa : 2009 2011 78 Nghiờn cu ch N c to v mt m s tớnh cht Vt lýý ca cỏc l p mng bỏnn dn h thhic suunphua (p-S SnS, n-SnS2, n-Sn2S3) nh hngg ng dng pin Mt M tri th h t mi thhõn thin v th i mụi trnng S phõõn b cỏc ngguyờn t troong mng c ng c kkim tra bnng cỏch kho sỏt b mt mng ch mapping Hỡnnh III.34 l nh mappinng phúng i 7000 lnn cho m mng thy cỏc nguyờn t phõn b ng u trờn b mt Sn S Cl Snn-S-Cl Hỡnh III.34: nh maapping th hin h s phõõn b cỏc ngguyờn t mng Sn2S3 yn qua ca mng ó c o trrờn thit b o ph hp p th v truuyn truy quaa UV-Vis hai h chựm tia dii bc súng g t 200 ữ 1100 nm Kt K qu o ph truy yn qua v b dy mnng c th hin trờn hỡnh h III.35 80 Sn2S3 T (%) 60 40 20 300 400 500 600 7000 800 9000 1000 11100 Bớc sóng (nm) Hỡn nh III.35: Ph P truyn qqua ca mnng Sn2S3 theo bc súnng H c viờn: oo c Tuõnn Khúaa : 2009 2011 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng Kt qu o cho thy mng Sn2S3 dy khong 800 nm cú truyn qua trung bỡnh l 60 % di bc súng t 550 ữ 1100 nm B rng nng lng vựng cm ca mng Sn2S3 c xỏc nh theo phng phỏp ngoi suy (h)2 = t ng th biu din cỏc giỏ tr (h)2 theo nng lng photon h l Eg = 2,61 eV (hỡnh III.36) 3.0 Sn2S3 2.0 1.5 -1 (h) (10 cm eV) 2.5 1.0 0.5 0.0 2.61 eV h (eV) Hỡnh III.36: th (h)2 ph thuc vo h ca mng Sn2S3 Hc viờn: o c Tuõn Khúa : 2009 2011 80 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng KT LUN Sau mt thi gian nghiờn cu lun ó hon thnh mc tiờu ca ti vi cỏc kt qu chớnh t c nh sau: 1) Trong phm vi nghiờn cu ó ch to thnh cụng mng bỏn dn SnS bng phng phỏp phun nhit phõn trc tip t cỏc tin cht SnCl2.2H2O v (NH2)2CS vi t l Sn/(S+Cl) = 0,91 theo cỏc thụng s cụng ngh ti u: nhit TS = 320 o C, nng CM = 0,24 M, tc phun v = ml/phỳt v khong cỏch gia u phun v l d = 40 cm Tớnh cht Vt lý ca mng ch to c trc v sau c kho sỏt bng cỏc phng phỏp hin vi in t quột (SEM), hin vi lc nguyờn t (AFM), ph tỏn sc nng lng (EDS), Alpha -Step, hp th UV-Vis v hiu ng Hall: Mng SnS sau ch to ti cỏc iu kin cụng ngh ti u cú b mt mn, ng nht v kt tinh thnh nhng ht cú kớch thc nh hn 100 nm Mng SnS to vi t l Sn/(S+Cl) = 0,91 l mng cú t l gn hp thc nht v thụng qua quỏ trỡnh x lý nhit mng tr nờn hon thin hn th hin t l Sn/(S+Cl) = 0,95 gn t l hp thc H s hp th ca mng SnS trc t 0,42.104 cm-1 Sau nhit 4h 200 oC h s hp th ca mng SnS ó tng lờn gp 4,7 ln so vi trc , t giỏ tr = 2.104 cm-1 ng thi b rng nng lng vựng cm ca mng SnS cng tng t Eg = 1,02 eV lờn Eg (4h) = 1,47 eV gn giỏ tr vựng cm ti u cho chuyn i quang in cc i pin Mt tri (Eg = 1,50 eV) iu ny c lý gii l cú s bay hi ca lng S v Cl d tha nm ti cỏc biờn ht mng v kt tinh ca mng cng c ci thin tt hn C th, mng SnS sau 4h ti 200 oC cú t l Sn/(S+Cl) = 0,95 v kớch thc ht nh hn 100 nm bao gm nhiu nano tinh th nh Hc viờn: o c Tuõn Khúa : 2009 2011 81 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng Bờn cnh ú vic tin hnh thay th dn 5, 10 v 15 % Cu cho Sn SnS ó to nhng mng cú h s hp th v b rng nng lng vựng cm tt hn Mng Sn0.90Cu0.10S ch to cú h s hp th cc i bng 1,38.104 cm-1 v Eg = 1,38 eV Sau 2h ti 200 oC mng Sn0.90Cu0.10S cú 2,6.104 cm-1 v giỏ tr b rng vựng cm tt nht l Eg = 1,50 eV ỳng bng giỏ tr vựng cm ti u s dng pin Mt tri Kt qu o hiu ng Hall cho thy mng Sn0.90Cu0.10S l bỏn dn loi p vi nng ht ti t n 1013 cm-3, in tr sut = 240 cm v linh ng Hall ca mng cú giỏ tr l H = 42,1 cm V-1s-1 2) ó nghiờn cu ch to thnh cụng mng SnS2 bng phng phỏp phun nhit phõn trc tip t cỏc tin cht SnCl2.2H2O (hoc SnCl4.5H2O) v (NH2)2CS vi t l Sn/(S+Cl) = 0,50 theo cỏc thụng s cụng ngh: nhit TS = 275 oC, nng CM = 0,05 M, tc phun v = ml/phỳt, khong cỏch gia u phun v l d = 40 cm Tớnh cht Vt lý ca cỏc mng SnS2 ch to cng c kho sỏt bng cỏc phng phỏp hin vi in t quột (SEM), hin vi lc nguyờn t (AFM), ph tỏn sc nng lng (EDS), Alpha Step v ph truyn qua UV-Vis: Mng SnS2 ch to ti cỏc iu kin ti u cú b mt mn ng nht, bỏm dớnh tt vi v cú t l hp thc Sn/(S+Cl) ỳng bng 0,50 Mng SnS2 l mng bỏn dn loi n cú vựng cm thng vi truyn qua cao Mng SnS2 cú b dy 370 nm cho phộp truyn qua 75 % ỏnh sỏng chiu ti vựng bc súng t 500 ữ 1100 nm v giỏ tr khe nng lng Eg = 3,0 eV Da trờn kt qu so sỏnh tớnh cht truyn qua ca cỏc mng SnS2, CdS v In2S3 ch to trc tip bng phng phỏp phun nhit phõn bc u ta cú th kt lun rng cú th s dng SnS2 thay th cho CdS v In2S3 vic ch to lp ca s cho pin Mt tri cng nh cỏc thit b quang in t khỏc 3) ó nghiờn cu v ch to thnh cụng mng Sn2S3 vi t l hp phn Sn/(S+Cl) = 0,71 bng phng phỏp phun nhit phõn trc tip t cỏc tin cht SnCl2.2H2O (hoc SnCl4.5H2O) v (NH2)2CS theo cỏc thụng s cụng ngh: nhit Hc viờn: o c Tuõn Khúa : 2009 2011 82 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng TS = 300 oC, nng CM = 0,20 M, tc phun v = ml/phỳt, khong cỏch gia u phun v l d = 40 cm Mng Sn2S3 cú truyn qua khong 60 % vựng bc súng t 550 ữ 1100 nm v b rng nng lng vựng cm Eg = 2,61 eV Cỏc kt qu nghiờn cu trờn ó cho thy cỏc vt liu thic sunphua (SnS, SnS2 v Sn2S3) cú nhng tớnh cht phự hp ng dng pin Mt tri th h th thõn thin vi mụi trng cng nh cỏc thit b quang in t khỏc Hc viờn: o c Tuõn Khúa : 2009 2011 83 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng HNG NGHIấN CU TIP THEO CA LUN VN Cỏc nghiờn cu sõu v rng hn na cn c tin hnh khng nh cỏc kt qu ban u v hng nghiờn cu tip theo ca lun nh sau: Kho sỏt sõu v rng hn nh hng ca thụng s cụng ngh quỏ trỡnh phun nhit phõn lờn tớnh cht ca cỏc mng thic sunphua Tip tc kho sỏt v nghiờn cu thờm nh hng ca cỏc cht khỏc lờn tớnh cht Vt lý ca cỏc mng thic sunphua Nghiờn cu ch to th nghim cỏc chuyn tip p-n (SnS/SnS2) ca pin Mt tri trờn c s cỏc mng thic sunphua Hc viờn: o c Tuõn Khúa : 2009 2011 84 Nghiờn cu ch to v mt s tớnh cht Vt lý ca cỏc lp mng bỏn dn h thic sunphua (p-SnS, n-SnS2, n-Sn2S3) nh hng ng dng pin Mt tri th h th mi thõn thin vi mụi trng TI LIU THAM KHO Acharya S., Srivastava O.N (1981), Electronic behaviour of SnS2crystals, Physica status solidi,A 65, pp 717723 Amalraj L., Sanjeeviraja C., Jayachandran M., (2002), Spray pyrolysised tin disulphide thin film and characterisation, Journal of 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Nghiên cứu chế tạo số tính chất Vật lý lớp màng bán dẫn họ thiếc sunphua (p-SnS, n-SnS2, n-Sn2S3) định hướng ứng dụng pin Mặt trời hệ. .. 11% Học viên: Đào Đức Tuân Khóa : 2009 – 2011 23 Nghiên cứu chế tạo số tính chất Vật lý lớp màng bán dẫn họ thiếc sunphua (p-SnS, n-SnS2, n-Sn2S3) định hướng ứng dụng pin Mặt trời hệ thứ thân thiện. .. 2011 Nghiên cứu chế tạo số tính chất Vật lý lớp màng bán dẫn họ thiếc sunphua (p-SnS, n-SnS2, n-Sn2S3) định hướng ứng dụng pin Mặt trời hệ thứ thân thiện với môi trường Hình III.19: Phổ hấp thụ màng