Dear fellow scientists:
I am working on fabrication of nonporous Anodised Aluminum Oxide. I am performing the electrolysis in 0.3M oxalic acid at 40V (CV mode in the power supply). However, recently I have started to observe that after a while the mode automatically switches from CV to CC and the substrate (Al coated Si) starts emitting fumes. I believe that it may be due to the decrease in the load (between cathode and anode) which causes increase in the current so the power supply starts changing the voltage to satisfy V=IR relationship. I think it might be due to the consumption of the entire Al (formation of deep pores) and when the electrolyte comes in contact with Si, the load drops and current increases. Do you think this might be the case or are there any other explanations for this?
Verify the nominal power of your source and if your experimental conditions are close to this limit or not.
try to make experiment with Al sheet and see if this CV-CC transition happen or not ?
then you can compare with Al coated on Si . Also it depends on thickness of Al you coated on Si , How much is the thickness of Al ?
Hi Alana, the Al thickness is 400nm. the cv to cc switchover happens after 2 minutes so I’m guessing the entire Al is consumed in that time, causing the load to decrease and current to increase.
then try to anodize silicon only and this should give you same current relation after dissolution
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