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Frontiers of Optoelectronics

Front. Optoelectron.    2015, Vol. 8 Issue (3) : 298-305     DOI: 10.1007/s12200-014-0372-z
High conductive and transparent Al doped ZnO films for a-SiGe:H thin film solar cells
Qingsong LEI(),Jiang LI
School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
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Al doped zinc oxide (AZO) films were prepared by mid-frequency magnetron sputtering for silicon (Si) thin film solar cells. Then, the influence of deposition parameters on the electrical and optical properties of the films was studied. Results showed that high conductive and high transparent AZO thin films were achieved with a minimum resistivity of 2.45 × 10-4 Ω?cm and optical transmission greater than 85% in visible spectrum region as the films were deposited at a substrate temperature of 225°C and a low sputtering power of 160 W. The optimized films were applied as back reflectors in a-SiGe:H solar cells. A relative increase of 19% in the solar cell efficiency was achieved in comparison to the cell without the ZnO films doped with Al (ZnO:Al).

Keywords Al doped zinc oxide (AZO) films      magnetron sputtering technology      growth      electrical and optical properties      a-SiGe:H solar cells     
Corresponding Authors: Qingsong LEI   
Online First Date: 04 April 2014    Issue Date: 18 September 2015
 Cite this article:   
Qingsong LEI,Jiang LI. High conductive and transparent Al doped ZnO films for a-SiGe:H thin film solar cells[J]. Front. Optoelectron., 2015, 8(3): 298-305.
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Qingsong LEI
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Fig.1  Influence of working pressure on resistivity, carrier concentration and Hall mobility of AZO thin films
Fig.2  Influence of substrate temperature on resistivity, mobility and Hall concentration of AZO thin films
Fig.3  Influence of sputtering power on resistivity, carrier concentration and Hall mobility of AZO thin films
Fig.4  Influence of working pressure on transmission and band gap of AZO thin films
Fig.5  Influence of substrate temperature on transmission and band gap of AZO thin films
Fig.6  Influence of sputtering power on transmission and band gap of AZO thin films
Fig.7  Structure of a-SiGe:H solar cells with (a) and without (b) ZnO:Al back reflector
Fig.8  I-V characteristics of a-SiGe:H solar cells with and without ZnO:Al back reflector
type Voc/V JSC/(mA·cm-2) FF η/%
without AZO back reflector 0.83 13.90 0.62 7.15
with AZO back reflector 0.84 14.65 0.70 8.51
Tab.1  Performances of p-i-n single junction a-SiGe:H solar cells prepared with and without AZO films back reflector
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