Plans for the development of amorphous cell accelerated test measurement instrumentation are outlined. Diagrams for an 11-lamp ELH solar simulator and ac light source instrumentation are given. Examples of ac and dc analysis graphs are also provided

Lathrop, J. W.

English

NASA Technical Reports Server

ACCELERATED STRESS FACTORS AND 
FAILURE/DEGRADATIGA MECHANISMS 
IN TERRESTRIAL SOLAR CELLS 
CLEMSON UNI'.'ERSITY 
Jay W. Lathrop 
-7 REPEATABILITY ERROR I% + 
ELECTRICAL / MEASUREMENT 
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VISUAL / VISUAL 
INSPEC ?1 INSPECTUN 
INSPECTION 
tow POWLR MAGNIFICATION 
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Planned Development of Amorphous-Cell 
Accderated Test Msasurement lnstrurnentatiorr 
PHASE 1 I PHASE 2 PHASE 3 
LIGHT SOURCh 
ADDED w 
11-LAW ELM 
12-INCH SQR 
AC AC 
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https://ntrs.nasa.gov/search.jsp?R=19850024138 2020-03-22T19:51:56+00:00Z
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MODLJLE DEVELOPMENT AND ENGINEERING SCIENCES 
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MODULE DEVELOPMENT AND ENGINEERING SCIFKES 
Ac Light-Source Instrumentation 
ELW solar 
t  mul la lor 
d ~ g ~ l a l  
current source I:&- 
MODULE DEVELOPMENT AND ENGINEERING SCIENCES 
Timing of Measurements When Ac Light Source Is Used 
MODULE DEVELOPMENT AND ENGINEERING SCIENCES 
Crystalline Silicon Cell: Dc Analysis 
11 2 0 4 
Cell voltage [Vo l t s )  
MODULE 
. . 
DEVELOPMENT AND ENGINEERING SCIENCES 
Crystalline Silicon Cell: Ac Analysis 
MODULE DEVELOPMENT AND ENGINEERING SCIENCES 
Intensity Monitcrhg and Adjustment 
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MODULE DEVELOPMENT AND ENGINEERING SCIENCES 
Simulated Amorphous Reference Cell 
F l l c r r  1 
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F i l t e r  2 
MODULE DEVELOPMENT AND ENGINEERING SCIENCES 
$ 
stress levels 20 hr.@ temp. shown) & 
MODULE DEVELOPMENT AND ENGINEERING SCIENCES 
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Accelerated stress factors and failure/degradation mechanisms in terrestrial solar cells

Results of an ongoing research program into the reliability of terrestrial solar cells are presented. Laboratory accelerated testing procedures are used to identify failure/degradation modes which are then related to basic physical, chemical, and metallurgical phenomena. In the most recent tests, ten different types of production cells, both with and without encapsulation, from eight different manufacturers were subjected to a variety of accelerated tests. Results indicated the presence of a number of hitherto undetected failure mechanisms, including Schottky barrier formation at back contacts and loss of adhesion of grid metallization. The mechanism of Schottky barrier formation is explained by hydrogen, formed by the dissociation of water molecules at the contact surface, diffusing to the metal semiconductor interface. This same mechanism accounts for the surprising increase in sensitivity to accelerated stress conditions that was observed in some cells when encapsulated

Accelerated stress factors and failure/degradation mechanisms in terrestrial solar cells

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