There are multiple available, however, I think at the stage of Post Doc or even for PhD, just express instead of impressing. Use of Jargons and heavy vocabulary should be avoided as much as possible. Try to be to the point.
Dear Prof. X I am XX, a Ph.D. candidate in the XX group of YY University, which is under the supervision of Prof. ZZ.
I am about to finish my Ph.D. study (in the submission phase) which is about using different XX methods (X, Y, Z) for the problem of XX, and currently, I am looking for postdoc opportunities relevant to my skills and interests.
I studied your recent research and projects and I noticed you have a strong research theme in XX and YY. I am really interested in your ongoing topics of ZZ and XYX, and I liked your publications which focus on DD and FF.
Therefore, I am really interested to know if you have any open postdoc position at your lab regarding similar topics in XX and YY. I have attached my CV for your view, but I also welcome any opportunity to discuss the possibilities with you in any formal/informal meeting.