Turn off monitor PowerShell

Use the following PowerShell script to turn off monitor(s):

Add-Type -TypeDefinition @"
using System;
using System.Runtime.InteropServices;

public class MonitorPower {
    [DllImport("user32.dll")]
    public static extern int SendMessage(int hWnd, int hMsg, int wParam, int lParam);
    
    const int HWND_BROADCAST = 0xffff;
    const int WM_SYSCOMMAND = 0x0112;
    const int SC_MONITORPOWER = 0xF170;

    public static void Off() {
        SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, 2);
    }
}
"@ -Language CSharp

[MonitorPower]::Off()