Samsung makes a real good monitor and I don't believe that Dell actually makes thier monitors but rather gets them from another supplier. Can you be a little more specific about you question , are you trying to find out if a company is making an all led monitor and not just a led back lighted one?
Led refers to the backlight, there is no such thing as a led pixel as they cannot be made that small for a pc monitor. Dell does make their own lcds. Each monitor has it's pros and cons even within the same company.