Effect of Vacuum Rapid Annealing Treatment on Performance of CIGS Solar Cells

doi:10.15541/jim20140182

Abstract

Abstract:

CIGS absorber layers were prepared by sequential sputtering/selenization method. Based on that, CIGS solar cells were fabricated with a structure of glass/Mo/CIGS/CdS/i-ZnO/ZnO:Al/Ni-Al grid. The influences of annealing treatment on the performance of CIGS solar cells were investigated. By optimizing annealing condition, the cell efficiency increased from 4.91% to 14.01%. Further investigation revealed that the post-annealing treatment had two advantages. Firstly, it facilitated the diffusion of Cd ions into CIGS surface to substitute the Cu vacancies. Thus, the surface of CIGS converted from p-type to n-type conduction, leading to the shift of p-n junction from CIGS/CdS interface into the CIGS layer. Therefore, the recombination centers at the p-n junction were greatly reduced. Secondly, most H₂O molecules being adsorbed on the CIGS surface were eliminated by annealing, which improved the uniformity of electrical properties and band-gap of CIGS layer, resulting better performance of CIGS solar cell.

Key words: CuInxGa1-xSe, annealing, sputtering/selenization sequential method, uniformity, homojunction

CLC Number:

TM914

TIAN Li, ZHANG Xiao-Yong, MAO Qi-Nan, LI Xue-Geng, YU Ping-Rong, WANG Dong. Effect of Vacuum Rapid Annealing Treatment on Performance of CIGS Solar Cells[J]. Journal of Inorganic Materials, 2015, 30(1): 35-40.

Figures/Tables 12

References 22

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Parameter^*	Before annealing							After annealing
Parameter^*	1#	2#	3#	4#	5#	6#	Ave	1#	2#	3#	4#	5#	6#
V_oc/mV	402	419	417	412	417	415	414	468	471	519	568	470	367
J_sc/mA	33	27	32	29	32	31	31	35	35	37	38	35	16
R_s/Ω	6.2	7.42	7.1	5.2	7.1	7.2	6.7	4.2	4.1	3.6	2.7	6.5	10.9
R_sh/Ω	34	61	38	33	38	37	40	57	244	345	1480	58	45
FF	0.364	0.386	0.354	0.410	0.354	0.349	0.370	0.449	0.494	0.521	0.649	0.373	0.344
η/%	4.83	4.35	4.67	4.91	4.67	4.42	4.64	7.25	7.99	10.19	14.01	6.07	1.38
(Δη/η₀)/%	-	-	-	-	-	-	0	56	72	120	202	31	-70

Parameter^*	Before annealing							After annealing
Parameter^*	1#	2#	3#	4#	5#	6#	Ave	1#	2#	3#	4#	5#	6#
V_oc/mV	402	419	417	412	417	415	414	468	471	519	568	470	367
J_sc/mA	33	27	32	29	32	31	31	35	35	37	38	35	16
R_s/Ω	6.2	7.42	7.1	5.2	7.1	7.2	6.7	4.2	4.1	3.6	2.7	6.5	10.9
R_sh/Ω	34	61	38	33	38	37	40	57	244	345	1480	58	45
FF	0.364	0.386	0.354	0.410	0.354	0.349	0.370	0.449	0.494	0.521	0.649	0.373	0.344
η/%	4.83	4.35	4.67	4.91	4.67	4.42	4.64	7.25	7.99	10.19	14.01	6.07	1.38
(Δη/η₀)/%	-	-	-	-	-	-	0	56	72	120	202	31	-70

*	n/ (×10¹⁶, cm^-1)	μ /(cm²·V^-1·s^-1)	ρ /(Ω·cm)	Type -
As-grown	7.92	2.15	37.63	P
Annealed	3.16	4.32	46.32	P
24 h	5.44	2.45	42.65	P

*	n/ (×10¹⁶, cm^-1)	μ /(cm²·V^-1·s^-1)	ρ /(Ω·cm)	Type -
As-grown	7.92	2.15	37.63	P
Annealed	3.16	4.32	46.32	P
24 h	5.44	2.45	42.65	P

*	RSD_V_oc/%	RSD_J_sc/%	RSD_FF/%	RSD_η/%
As-grown	3.94	3.35	7.77	8.71
Annealed	2.60	2.29	5.14	7.24