export – create a file by RunProcess and Powershell

In(1) RunProcess({"powershell", "echo abc"}, "StandardOutput")
Out(1) abc (*as a string*)

In(2) RunProcess({"powershell", "echo abc > xyz.txt"}, "StandardOutput")
Out(2) (*nothing is written*)

After Out(2), I expected there should be xyz.txt somewhere on my disk, but no such file was generated.

Can I create a file using RunProcess and powershell on mathematica ?

For example,

RunProcess({"powershell", "dir > xyz.txt"}, "StandardOutput")

or

RunProcess({"powershell", "get-clipboard > xyz.txt"}, "StandardOutput")

Above codes are not working.. Can you write correct codes for my intention?
I tried to find more about RunProcess, but I couldn’t find satisfactory reference. If you know more about RunProcess can you teach me?