Transcript Round Robin Session

Round Robin Session
Ways of Comparison
• Stable Samples
• OPV
• Black box – unknown with filters over Si
– Need to measure QE and Efficiency
• Send a KG5 reference cell
• Need to send out a guideline on how to
measure efficiency
Steps
• Develop procedures
• Do black box round
Measurement Procedures
•
How to measure efficiency – Keith, Matt, Moritz (1-2 months)
– How to measure an IV curve (is bias rate to high – does it matter which way you sweep
– Area definition jsc with and without an aperture
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Small under a cm2
If we are a large area technology 1cm2 is a minimum
Physics community does not want 1 cm2
Key is to define an aperture approach. Under a certain area must use an aperture. Should be round
or square or rectangle
How you make contact can matter – edge or top. (In on SnOx ext around boarder) Add additional
metal. Separate voltage and current contacts a no/no
If no aperture then must be over 1 cm2
Should their be a minimum area ?
Aperture needs to be thin, could be part of metallization mask
User should place the aperture
Need to include details of cells, filters and light sources
IPCE data needs to be included – Sean will provide spread sheet for IPCE to current
Need to make sure that the QE and Jsc are consistent
Jsc from spectral response based on inter-comparison no better than +/- 10%
Do measurement as a function of light intensity is useful but not required
Submitted cells need to have either the aperture on them or room to place an aperture
ASTM G173 will be new solar spectrum standard
Include a bibliography of useful references etc.
Try to define low cost simulator and QE system
• Light sources
– Filaments (kg5 or kg filter) can be pretty solar like
– Should run a same current and change distance to
change the light level
– Xenon arc expensive and not good data
– Good procedures compensate for spectral error
• Reference Cell
– KG5 filtered Si cell – filter can be on detector as
well. Use other filters to match device.
OPV cert. Measurements
• Ultimately 1 cm2
• No real package requirements – need to define
aperture --- mandatory under 1 cm2
– Minimum area?, Aspect ratio cannot be to high
(<100:1)
• Historically stability has not been an issue
– Amorphous a stabilized number
– Dark wait time – could be up to 4 weeks – nitrogen
box overpressured
– How much time in air and light – 1 min in each for
both - time constants
Round Robin
•
•
•
•
•
•
If OPV then sample would have to be stable of each cycle.
First round robin send out KG filtered Si solar cell.
Hammatsu can build a set of “identical” devices.
Have a device for P3HT and for Low Band Gap, CuPc/C60
Geometry constraints could be a problem
Start process now – have measurements done in 6 month
(october 1 to send out devices) and write up follows
(published in journal) – first send out devices and get data
back and then feed back actual data
• There will be a second round in about a year to be better
defined then but the study will get an OPV device from
commercial supplier
• Participant – blanket email to see who wants to participate.
Up to 30 possible.
• Participants are identified but not their data then there is a
paper for original state of the measurements and a second
Issues
• Package size
• Simulator defines the area a problem
• Needs
–
–
–
–
–
–
–
–
–
–
–
–
–
Need to identify host -NREL will host
Participants – email response
Package – 1 cm2 should work – need to define rest with participants.
Standardized spectra – CuPc/C60, P3HT, Low band gap
One for P3HT, one for long wavelength polymer, one for other
NREL/DU will do P3HT/
Heeger/Konarka/Plextronics Small band gap
Moritz Riede small molecule
Put temperature sensor in the package
Do we require a QE measurement for the cells. – yes
If it is a good blind experiment then no one sees data till the end
How often do you repeat
We keep the packages around and can send them back out for requalification
– Temperature – 25
• Spectral Error (can be
large)
– Possible error if not
included