What precursor materials should I use for Cadmium and Sulphur and what are the optimal deposition conditions (i.e. concentration, time, temperature and pH level) for the synthesis of Cadmium Sulphide (CdS) via Chemical Bath Deposition (CBD). I'm struggling to fabricate thin film CdS that is less than 100nm and is uniform and pinhole free. Any help would be greatly appreciated. Thanks
Dear Abul,
You can use the method described in the paper at the link: Article Chemical Bath Deposition of CdS layer for Thin Film Solar Cell
Best wishes
Dear Abul Hasnath :
In addition to Mr. Zerky useful reference I want to share with you the formulation I use for CdS Chemical Bath deposited thin films (see the attached file please)
This is an Ammonia-free formulation, this is an upper hand at the moment of preparing the solutions and also it helps you to have better control of the pH of your bath, since you don't have to deal with an ammonia evaportation rate, which could lead to a destabilization of the pH, when long periods for the baths are conducted.
As for the tips, mainly:
- Pour the water first into the beaker, before pouring any of the other prepared solutions.
- Keep stiring the bath during all times; from the moment you pour in the CdCl2 solution, to the moment just before taking the substrates into the beaker.
- Always place the substrates oriented with the surface you want to deposit on facing the walls of the beaker (this will be the "useful" side)
- On your first baths, monitor the pH constantly (maybe each 20 or 30 min, depending on the duration of the bath), so you can be sure the pH is around 12.3 all the time (this value of pH is associated only for this bath only for the formulation below, for other formulations and precursors the pH could be different). One of the most important variables you have be sure you can have a relative good control of, is pH.
I am attaching as well two of the references where you can find this procedure, so you can have the documentation about it.
Best Luck,
Regards !
Refer the below article may provide clarification to your quest
Pinhole free thin film CdS deposited by chemical bath using a substrate reactive plasma treatment
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