Backup file new files only with Powershell - powershell

Question

I am writing a Powershell script to add only new files to a backup. I have a back up folder and then I add a new file after a minute and it copies all the contents where I only want the new file copied.
So as you can see I am get the files and backing them up in the $Destination folder with the timestamp. After a couple of minutes I add a new file and run the script again and it copies the new added file along with all the other files. I only want the new added file to be copied to the new backup.
What do I need to do to incorporate this??
This is my code:
function BackupArtifacts {
Param(
$FileLocation = "C:\TempCopy",
$Destination = "C:\TempCopyBackUp_" + $TimeStamp,
$StartRange = -100,
$NumberOfDays = 5
)
New-Item -ItemType Directory -Force -Path $Destination
$count = 0
foreach ($fileList in Get-ChildItem $FileLocation -recurse)
{
if ($fileList.LastWriteTime -ge ($(Get-Date)).AddDays($StartRange))
{
#Check if file already exists
try {
Copy-Item $fileList.FullName -Destination $Destination -Recurse
Write-Host $fileList.FullName
$count ++
} catch {
Write-Error $_
}
}
}
Write-Host "Backup complete, Number of files backed up:" $count
}
BackupArtifacts $FileLocation $Destination $StartRange $NumberOfDays