The PeekTemplateSettings exposes properties and thus does not require an object in order to set them. You can see how this is done in the following demo's code-behind: http://demos.telerik.com/aspnet-ajax/tilelist/examples/animations/defaultcs.aspx
The PeekTemplate itself is basically a controls container, so an HTML string set is trough a literal, as shown in the same demo is one way to use it, another is to add the desired controls direcly to the PeekContentContainer.
Information on the matter is also available here: http://www.telerik.com/help/aspnet-ajax/tilelist-server-side-tile-object.html
. I am attaching screenshots with the relevant information marked as a reference.
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