St udy of struct ure and optical properties of Cu2doped ZnO nanofilms prepared by RF magnetron sputtering

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1 ( ) Vol No11 Journal of Northwest Normal University (Natural Science) 37 Cu ZnO 1, 1, 2, 1, 1, 1 (1., ; 2., ) : ( RF) Cu ZnO. X (XRD) (AFM) (SEM), ZnO. : (002), c ; 3, 400 nm (3114 ev, ), 444 nm(21 78 ev, ), 484 nm (2156 ev, ).,. Cu, Eg, ev 2199 ev., Cu,. : AFM ; ; Cu ZnO ; ; : O : A : (2010) St udy of struct ure and optical properties of Cu2doped ZnO nanofilms prepared by RF magnetron sputtering MA Shu2yi 1, MAO Lei2ming 1, MA hui 2, SHI Xin2f u 1, ZHOU Ting2ting 1, DIN G Ji2jun 1 (1. College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou , Gansu, China ; 2. Department of Physics and Electronic Technology, Chaohu University, Chaohu , Anhui, China) Abstract : ZnO films doped wit h different Cu co ncent ratio n are p repared o n glass subst rate by RF magnetron sp uttering system. The structural and morp hology of t he samples are investigated by X2 ray diff raction ( XRD), atomic force microscopy ( A FM) and scanning electron microscopy ( SEM), and t he stress in t he ZnO thin films is analyzed. The result s show t hat all t he samples have a strong diff raction peak and high p referential orientatio n in t he ( 002 ) crystallograp hic directio n. Three peaks have been observed f rom t he PL spectra of t he all samples, 395 nm (3114 ev,violet), 446 nm (2178 ev,blue) and 488 nm (2154 ev,blue). It is concluded t hat the violet peak may correspond to t he exciton emission, the blue emission corresponds to t he electron transition f rom t he bottom of t he conduction band to t he acceptor level of zinc vacancy ; t he optical test shows t hat the optical band gap Eg are decreased within t he increase of Cu doped in ZnO, t he band gap decrease f ro m ev to ev gradually. It is al so fo und t hat t he transmission rate is decreased rapidly when t he Cu concentration is increase. Key words : A FM ; p hotoluminescence ; Cu doped ZnO films ; optical band gap ; transmission : ; : : ( ) ; (0710RJ ZA105) ; ( KF205203) : (1965 ),,,,,.. E2mail :

2 38 ( ) 46 Journal of Northwest Normal University (Natural Science) Vol146 ZnO 2, ( 3137 ev) (60 mev),. ZnO,,,,,, [125 ],. ZnO,,,., Mn V Cr Fe CO Ni ZnO Cu ZnO [ 6 ]. Cu ZnO., Cu ZnO, Cu Cu2ZnO J GP560BIV, Cu 15 min, 3, N Pa, , 60 mm, 4 mm, 6 cm. ZnO ,, Cu ZnO 1 100, 2 100, 3 100, Cu 1, 2, 3, ZnO Cu. (Ar ) ( O ), Ar 20 cm 3 s - 1, O2 10 cm 3 s - 1, 80 W., 3 Pa, 1 h, h. Cu ZnO, A, Cu ZnO, B (1 ) C(2 ) D (3 ). 112 D/ Max22400 X Cu ( K, = nm). SPM29500 ( A FM) (SEM). PL RF5301,, 250 nm. SH IMADZU UV2 2550PC, nm Cu2ZnO XRD 1 c (002), ZnO (002) [ 7 ]. D ZnO (101),, ZnO. Cu, (002), B C D,. 1 Cu ZnO XRD Fig 1 X2ray diff raction patterns of ZnO films deposited under different Cu content s Scherrer d = 019 cos. ( 1 ), X ( nm),, (002). = 2c13 - c33 ( c11 + c12 ) c - c0 = c c - c0 c0 c0. ( 2 )

3 : Cu ZnO 2010 No11 Study of structure and optical properties of Cu2doped ZnO nanofilms prepared 39 c11, c12, c13, c33 ZnO, c c0 ZnO, c0 = nm, c.. Tab Cu ZnO The crystalline size and stress of different Cu contents doping on ZnO films 2 / Crystalline Lattice FWHM/ size/ nm constant/ nm A (pure ZnO) Stress / GPa B(1 ) C(2 ) D(3 ) , B C D, Cu, (002),,, [ 8 ]. B, C, ( ), Cu. Cu 3, ( ).,, Cu 1 + Cu 2 +. Cu 1 + Cu 2 + Zn , 01072, nm [ 9 ]. (002),, Cu Zn 2 + Cu 2 + [ 10 ] SEM A FM, SEM., Cu,, 2. SEM, A, Cu, C,,,. Cu, 3,,,,. XRD. Cu, X ( EDS) C (2 ) D (3 ) ( 2 3). Tab 2 Element Line 2 Cu ZnO SEM Fig 2 SEM patterns of different Cu doping concentration on ZnO films 2 2 Cu ZnO EDS EDS of ZnO films deposited under 2 Cu content s measured at room temperature Weight Atom Formula Compnd / O K O Si K Si Ca K Ca 3118 Cu K Cu 4111 Zn K Zn Total Element Line 3 3 Cu ZnO EDS Tab 3 EDS of ZnO films deposited under 3 Cu content s measured at room temperature Weight Atom Formula Compnd / O K O Si K Si 5119 Ca K Ca 1182 Cu K Cu 5121 Zn K Zn Total

4 40 ( ) 46 Journal of Northwest Normal University (Natural Science) Vol Cu. C D Cu , ZnO Cu. (A FM), 3 A ( Cu) C ( 2 ) D ( 3 ) A FM., A C, ( Rms), 31722, nm. C,,, c. D, ( Rms), nm,,.., D XRD (002) (101), c, a ( PL) 4 Cu ZnO PL. B C D B C D., 3, 400 nm, 444 nm 484 nm. Cu, PL 400 nm 444 nm. 484 nm. 3 Cu ZnO A FM Fig 3 A FM patterns of different Cu doping concentration on ZnO films 4 Cu ZnO PL Fig 4 PL spectra of samples deposited under different Cu content s at room temperature 400 nm., 2,., C,., ZnO,, ZnO, [11 ],. Cu,,, ZnO,,,. PL, 444 nm, Cu. Zni. Zni,, ZnO,,. Zn i.

5 : Cu ZnO 2010 No11 Study of structure and optical properties of Cu2doped ZnO nanofilms prepared 41 Zn i ev., [12 ] ZnO Zn i 015 ev,., 484 nm.. Cu,. Cu 1 + (01096 nm) Cu 2 + (01072 nm), Cu 1 + Zn 2 + (01074 nm), ZnO ; Cu 2 + ( nm) Zn 2 +, ZnO. Cu ZnO Cu 1 + Cu 2 + Cu 2 + 3, ZnO., Cu, Cu Cu 2 + ZnO, Zn 2 +, Cu, ( V Zn ),.,. [13 ] , ZnO ( nm) 90,. Cu, Cu2ZnO ( , , ). Cu2ZnO. Cu,,.,, T = (1 - R) 2 e - ad [14 ]. h = A ( h - Eg) 1 2 ( 3 ) (, A, h, h, Eg ) ( h ) 2 h 6. = 0 Eg [15 ]., Cu,, Al ZnO [16 ] Cu ( h ) 2 h Tab 4 Fig 6 Plot of ( h ) 2 vs the photon energy for different Cu contents doped ZnO films 4 Cu Eg of ZnO films deposited under different Cu content s measured at room temperature A B C D / / ev Cu 2, d sp2d [17219 ]. 3 5 Cu ZnO Fig 5 Transmission spectra of ZnO films deposited under different Cu content s measured. 5, Cu,,. Tauc Cu2ZnO, Cu ZnO. XRD SEM ZnO c., Cu,, ;,, (002) ;. 3, 400 nm (3114 ev, ), 444 nm (2178 ev, ),

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