Issue when setting a cell value string with emoji, java dhatim/fastexcel

Question

Code is executed without error, but when i open the xlsx file i see the following

I changed the xlsx file to zip, and opened xl/sharedStrings.xml file This symbols where there �&#xde01; Here is sharedStrings.xml

The file <?xml version="1.0" encoding="UTF-8" standalone="yes"?><sst xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main" count="183" uniqueCount="1"><si><t>&#xd83d;&#xde01;</t></si></sst>