They are LED backlit. They are the same model LG IPS panel as what is used in the Apple 27" displays.
http://www.techrepublic.com/photos/crac ... 041?seq=33
Catleap (scroll to OC vs Non-OC montors and expand the monitor internals:
http://www.overclock.net/t/1225919/yama ... nitor-club
Read through the OC Catleap club thread to learn more about the monitor.