DocumentCode :
460181
Title :
Boundary Conditions for the Industrial Production of LFC Cells
Author :
Grohe, A. ; Fleischhauer, B. ; Preu, R. ; Glunz, S.W. ; Willeke, G.P.
Author_Institution :
Fraunhofer Inst. for Solar Energy Syst., Freiburg
Volume :
1
fYear :
2006
fDate :
38838
Firstpage :
1032
Lastpage :
1035
Abstract :
The `Laser-Fired Contact´ (LFC) process scheme developed at Fraunhofer ISE is a fast, easy applicable and industrially feasible way of introducing the `Passivated Emitter and Rear Cell´ (PERC) structure into solar cell production. Because the standard industrial production scheme needs to be adapted to the LFC process several further aspects have to be taken into account. It is already well known that thermal influence like an annealing step is beneficial for some dielectric layers as well as for LFC. Therefore experiments have been carried out to investigate the influence of temperature, duration and ambient atmosphere of a final annealing step on the performance of LFC rear sides. Results showed that in contrast to the standard ISE clean room process the solar cell efficiencies did not deteriorate by using a low-cost and contaminated metal belt furnace instead of a clean quartz tube. Additionally not even the forming gas ambient was necessary enabling the use of cheaper gases like nitrogen or cleaned pressure air. The duration and temperature can be adapted to the requirements of other process steps, since short and hot conditions result in the same efficiencies as cool and long ones. Furthermore the standard LFC process was adapted to the use of thicker aluminum layers as well as aluminum/silver stack layer systems. Pure aluminum does not enhance the LFC quality but enables lower conduction losses, the stack system is necessary for standard soldering processes for module integration. Both layers can be used with no loss in solar cell performance
Keywords :
annealing; clean rooms; contamination; furnaces; semiconductor device manufacture; solar cells; soldering; Fraunhofer ISE; LFC cells; PERC structure; Passivated Emitter and Rear Cell; aluminum layers; aluminum/silver stack layer systems; annealing; boundary conditions; clean quartz tube; clean room process; cleaned pressure air; contamination; dielectric layers; industrial production; laser-fired contact process; metal belt furnace; nitrogen gas; solar cell production; soldering process; Aluminum; Annealing; Atmosphere; Belts; Boundary conditions; Dielectrics; Furnaces; Photovoltaic cells; Production; Temperature;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Photovoltaic Energy Conversion, Conference Record of the 2006 IEEE 4th World Conference on
Conference_Location :
Waikoloa, HI
Print_ISBN :
1-4244-0017-1
Electronic_ISBN :
1-4244-0017-1
Type :
conf
DOI :
10.1109/WCPEC.2006.279295
Filename :
4059807
Link To Document :
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