An ultra-high charge density electret is disclosed. The ultra-high charge density electret includes a three-dimensional structure having a plurality of sidewalls. A porous silicon dioxide film is formed on the plurality of sidewalls, and the porous silicon dioxide film is charged with a plurality of positive or negative ions.

An electret element includes: an electret film that contains silicon oxide; and a protective film formed over the electret film and constituted of aluminum oxide deposited through an atomic layer deposition method.

An electret element includes: an electret film that contains silicon oxide; and a protective film formed over the electret film and constituted of aluminum oxide deposited through an atomic layer deposition method.

An ultra-high charge density electret is disclosed. The ultra-high charge density electret includes a three-dimensional structure having a plurality of sidewalls. A porous silicon dioxide film is formed on the plurality of sidewalls, and the porous silicon dioxide film is charged with a plurality of positive or negative ions.

A capacitance diode or variable capacitance diode includes first and second electrodes and a layer configuration disposed in contact-making fashion between the two electrodes. The layer configuration has, one after the other in a direction from the first electrode towards the second electrode, a layer formed of a ferroelectric material and an electrically insulating layer formed of a dielectric material having electrically charged defects. A method for producing a capacitance diode or a variable capacitance diode, a storage device and a detector including a capacitance diode or a variable capacitance diode are also provided.

A power generator includes an electret including a first charged surface and a second charged surface having opposite polarities, a first electrode partially formed on the first charged surface, a second electrode formed on the second charged surface, a third electrode disposed to face the first charged surface with a space, and at least one of a power storage unit or an output unit. The first charged surface has a current collecting surface that is exposed outward. The first electrode and the second electrode form a first power generating unit and the third electrode and the second electrode form a second power generating unit. The electret is formed by polarizing an electret material that includes an inorganic dielectric having a bandgap energy of 4 eV or more.

An electret element includes: an Si layer, an SiO.sub.2 layer formed at a surface of the Si layer; and an electret formed at the SiO.sub.2 layer near an interface of the SiO.sub.2 layer and the Si layer.

A power generator includes a power generating unit and at least one of a power storage unit or an output unit that is electrically connected to the power generating unit. The power generating unit includes an electret having a first charged surface and a second charged surface that are charged with opposite polarities, a first electrode formed on the first charged surface, and a second electrode formed on the second charged surface. The electret is formed by polarizing an electret material that includes an inorganic dielectric having a bandgap energy of 4 eV or more. At least one of the first electrode or the second electrode are partially disposed on the corresponding charged surface such that at least one of the first charged surface or the second charged surface has a portion as a current collecting surface exposed outward.

A method for manufacturing an electret material includes: an ion implantation step of implanting ions into an insulator; a heat treatment step of, after the ion implantation step, performing a heat treatment on the insulator by supplying energy from the outside; and a charging step of charging the ions in the insulator after the heat treatment step.

A capacitance diode or variable capacitance diode includes first and second electrodes and a layer configuration disposed in contact-making fashion between the two electrodes. The layer configuration has, one after the other in a direction from the first electrode towards the second electrode, a layer formed of a ferroelectric material and an electrically insulating layer formed of a dielectric material having electrically charged defects. A method for producing a capacitance diode or a variable capacitance diode, a storage device and a detector including a capacitance diode or a variable capacitance diode are also provided.