Phosphine oxide compound, organic electroluminescence element, production method and uses thereof

A method for producing an organic electroluminescence element, comprising the steps of:

• forming a phosphine oxide-containing layer by depositing a compound represented by the following formula (1) on a luminescent layer formed on an anode, and
• forming a cathode on the phosphine oxide-containing layer;
• wherein in the formula (1), plural R1 are each an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a halogen atom, or a hydrogen atom, and may be the same as or different from one another;
• and plural Ar are each a monovalent substituted or unsubstituted aromatic group optionally containing a hetero atom, and may be the same as or different from one another.