Electron emitting element having an electron acceleration layer, electron emitting device, light emitting device, image display device, cooling device, and charging device

An electron emitting element comprising:

• an electrode substrate;
• a thin-film electrode;
• and
• an electron acceleration layer sandwiched between the electrode substrate and the thin-film electrode,
• the electron emitting element (i) accelerating electrons in the electron acceleration layer at a time when a voltage is applied between the electrode substrate and the thin-film electrode and (ii) emitting the electrons from the thin-film electrode,
• the electron acceleration layer including (a) conductive fine particles and (b) insulating fine particles whose primary average particle diameter is greater than that of the conductive fine particles, and
• the electron acceleration layer includes aggregates of the conductive fine particles, the aggregates having an average particle diameter of 0.35 μm or less.

A method for manufacturing an electron emitting element that includes:

• an electrode substrate;
• a thin-film electrode;
• and
• an electron acceleration layer sandwiched between the electrode substrate and the thin-film electrode,
• the electron emitting element (i) accelerating electrons in the electron acceleration layer at a time when a voltage is applied between the electrode substrate and the thin-film electrode and (ii) emitting the electrons from the thin-film electrode,
• the method comprising the step of:
• forming the electron acceleration layer on the electrode substrate with a nano-colloidal solution of the conductive fine particles in a liquid state wherein the conductive fine particles have an average particle diameter of 0.35 μm or less in a colloid state.