d******e
发帖数: 1424 | 1 需要一个东西做ammonia的替代。能想到的简单点的如benzylamine,t-butylamine,
hydroxylamine。另外还有如Zn[N(SiMe3)2]2，Ph2CNH什么的。
请问还有什么简单的ammonia equivalent？Ammonium Acetate可以吗？ |
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l*****l
发帖数: 85 | 2 I have tried to follow Sargent group's procedure to make a thin film out of
PbS quantum dot. I spin-coated a film from a 150 mg/ml octane solution of
butylamine-capped PbS QDs. The spinning condition was 500 rpm for 60 seconds
. But the film qaulity was terrible. It was obviously not uniform at all.
Could anyone share some experiences in thin film fabrication with QDs? What
are the tricks?
Thank you. |
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t***3
发帖数: 100 | 3 Actually the film should be very smooth and shinny. Several tips that
might be helpful for you:
1) Stay in glovebox, otherwise PbS nanodots are oxidized very fast and
then you would see white waxy stuff on the film;
2) Make sure the butylamine ligand exchange is complete; if you have too
many oleic acid leftovers, the film would be terrible.
Hopefully it helps and good luck to you!
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l*****l
发帖数: 85 | 4 Thank both lenovodos and tj403 for the kind replies.
The problem actually is that both oleic acid-capped PbS and butylamine
exchanged PbS form small aggregates in octane. I expected those QDs can
completely dissolve in octance. But it did not happen. The films I got were
continous but with many tiny domains of aggregates.
I did everything from washing to exchange to spin coat in air. But with OA
the capping reagent, the QDs shoudl be readily dissolve/disperse in a
nonpolar solvent even PbO forms |
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l*****l
发帖数: 85 | 5 For some reason, I always had small aggregates even in the OA-PbS octane
solution. I expects that all QDs are capped with oleic acid. The capped PbS
should be easily dissolved in a non-polar solvent. There should not be any
aggregates. I can not explain why they were formed.
For the butylamine-exchanged QDs, there were even much more aggregates. I
feel that the QDs spacing have been reduced too much after exchanged with BA
. I guess there is some trick to control the exchange extent, but could n |
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