Process for preparing a thin layer of ferroelectric material

A process for preparing a thin layer of ferroelectric material based on alkali metal, exhibiting a Curie temperature, comprising:

• transferring the thin layer of ferroelectric material based on alkali metal from a donor substrate to a carrier substrate using a transfer technique including implanting atomic species into the donor substrate to produce an embrittlement plane delimiting the thin layer, which has a first, free face and a second face that is disposed on the carrier substrate after transferring the thin layer to the carrier substrate, wherein the donor substrate has a coefficient of thermal expansion close to that of the carrier substrate;
• applying a first heat treatment to the transferred thin layer at a temperature higher than the Curie temperature, the thin layer of ferroelectric material based on alkali metal exhibiting a multi-domain character upon completion of the first heat treatment;
• introducing protons into the thin layer after the first heat treatment;
• and
• after introducing the protons into the thin layer, applying a second heat treatment to the thin layer at a temperature lower than the Curie temperature and generating an internal electric field resulting in the thin layer of ferroelectric material based on alkali metal being made single domain.