Organic el device

1. An organic electroluminescence (EL) device, comprising:

a substrate;

an anode disposed on or above the substrate;

one or more functional layers disposed on or above the anode, the one or more functional layers including a light-emitting layer;

an electron transport layer disposed on or above the one or more functional layers, the electron transport layer containing organic compound-containing material; and

a cathode disposed on the electron transport layer and in contact with the electron transport layer, the cathode being light-transmissive, wherein

the electron transport layer has a relative permittivity of no less than 2 and no greater than 10 when supplied with an AC voltage having a frequency of no less than 1 MHz and no greater than 1 GHz, and

the electron transport layer includes a degraded layer in which indium or oxygen penetrates the electron transport layer, a depth of the degraded layer being at most equal to 15 nm.

2. The organic EL device of claim 1 , wherein

the electron transport layer has a layer thickness of no less than 30 nm and no greater than 150 nm.

3. The organic EL device of claim 1 , wherein

the cathode is formed by magnetron sputtering.

4. The organic EL device of claim 2 , wherein

the cathode is formed by magnetron sputtering.

5. The organic EL device of claim 3 , wherein

the cathode contains an electrically conductive oxide-containing material that contains at least one of In, Sn, Ti, Al, Zn and Ga in addition to O.

6. The organic EL device of claim 4 , wherein

the cathode contains an electrically conductive oxide-containing material that contains at least one of In, Sn, Ti, Al, Zn and Ga in addition to O.