Chemical bath deposition

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The chemical bath deposition ( English chemical bath deposition , CBD, or solution growth ) is a coating technique for deposition of thin layers . It is based on the controlled separation of poorly soluble salts from a solution .

Gerhard Brückmann laid the foundations for this deposition technique in 1933 when he first produced thin films of lead sulfide (PbS) from a solution containing lead acetate , thiourea and sodium hydroxide .

The procedure may be similar to a chemical vapor deposition (engl. Chemical vapor deposition , CVD) can be considered, wherein the substrate is not in a gas space, but in a solution. The deposition of the thin layers occurs through reaction of the ions or through agglomeration of the colloidal particles. This can be done, for example, by adding a complexing agent and heating the solution. On a laboratory scale, this can be done, for example, as follows. The substrate is immersed in the solution, which is in a beaker , and heated to 60 to 80 ° C. by a hot plate . A magnetic stirrer can be used for better mixing of the solution .

The method is characterized by low costs, as no expensive system technology is required, for example the vacuum system required for the CVD process. One container is essentially sufficient for the solution and the substrate. It is also considered a scalable technology, which means that the separation can easily be transferred from the laboratory scale to large-scale batch processing or continuous separation. The disadvantage of this method is that the solution is disposed of as waste after each separation.

Among other things, CBD is used for the deposition of chalcogenides , for example for the production of the cadmium sulfide layer (CdS) in thin-film solar cells .

literature

  • Antonio Luque, Steven Hegedus: Handbook of photovoltaic science and engineering . John Wiley and Sons, 2003, ISBN 978-0-471-49196-5 , pp. 585 .
  • Mirtat Bouroushian: Electrochemistry of Metal Chalcogenides . Springer, 2010, ISBN 978-3-642-03966-9 , pp. 132 ( limited preview in Google Book search).

Individual evidence

  1. ↑ Gerhard Brückmann: Preparation and Properties of thin lead sulfide layers with special consideration of their effect detector, I . In: Colloid Journal . tape 65 , no. 1 , 1933, pp. 1-11 , doi : 10.1007 / BF01428850 .
  2. ↑ Gerhard Brückmann: Representation and properties of thin lead sulfide layers with special consideration of their detector effect, II . In: Colloid Journal . tape 65 , no. 2 , 1933, pp. 148-161 , doi : 10.1007 / BF02585204 .
  3. ^ David B. Mitzi: Solution processing of inorganic materials . Wiley-Interscience, 2009, ISBN 978-0-470-40665-6 , pp. 200 ( limited preview in Google Book Search).
  4. ↑ Mirtat Bouroushian: Electrochemistry of metal chalcogenide . Springer, 2010, ISBN 978-3-642-03966-9 , pp. 132 ( limited preview in Google Book search).