How to write XML string in a tag using XMLSerialize [closed]

When I pass the string and generate it by XmlWriterSettings.xmlSerialize passing the data without special characters, it still generates as follows. Briefly, I have an xml document inside a tag.

<Valor>&amp;lt;![CDATA[&amp;lt;CFe xmlns:xsi=&amp;quot;http://www.w3.org/2001/XMLSchema-instance&amp;quot; xmlns:xsd=&amp;quot;http://www.w3.org/2001/XMLSchema&amp;quot;&amp;gt;