Transcript Bechler Scott sol 2014 sm

Environmental Effects
of Organometal Lead
Halide Perovskites
When Used in Solar
Cells
By Scott Bechler
Background
 With the growing energy crisis, research on solar
technology has been expanding rapidly
 One break through has been
Lead Halide
Organometal
Perovskites
 Efficiencies have grown from
6% to
19.3% in the last few
years
 Current silicon solar technologies operate at 25%
efficiency
 Perovskites can be manufactured with cheap materials
and relatively low-tech lab
Organometal Lead Halide
Perovskites
 Unstable– degrade quickly with contact to air or
moisture
 How much lead is leached and how will it affect the
environment?
Method (continued)
 Used two Environmental Protection Agency (EPA)
methods to test the cells’ tendency to leach lead
 Synthetic Precipitation Leaching Procedure: pH=4.2 Acid
Rain
 Toxicity Characteristics Leaching Procedure: pH=5.0
Landfill Conditions
 Rotated cells in bottles end-over-end for
hours
18
Method
 Received cells with various layers
Epoxy
Silver
Organic Layer
Perovskite
Titanium Oxide
Glass
Results
Before Acid Rain Leach
Perovskite
Glass
Full Cell
After Acid Rain Leach
Results (Continued)
Acid Rain % Leached
Landfill Conditions % Leached
39
54
42
57
Not tested
10
21
Not Tested
26
Not tested
14
Not tested
Results
Before Acid Rain Leach
Perovskite
Glass
Full Cell
After Acid Rain Leach
Results (Continued)
Acid Rain % Leached
Landfill Conditions % Leached
39
54
42
57
Not tested
10
21
Not Tested
26
Not tested
14
Not tested
Future Plans
 Knowing the total initial lead content
 Determine percent leached
 What do the lab results mean in terms of real
environmental scenarios?
 Which layers are better at minimizing lead leaching?
Acknowledgements
 Thanks to Sarah Jane White, Satish Myneni, Jim
Shine, Cody Schlenker, Matt, Becky