University of Houston System

Naijuan Wu

Alex Ignatiev

Xin Chen

Shangqing Liu

Rabi Ebrahim

Kristina Young-Fisher

Shangquiq Liu

Yansong Chen

Yuxiang Zhou

JainRen Li

An electric-pulse-induced-resistance change device (EPIR device) is provided which is a resistance switching device. It has a buffer layer inserted between a first active resistance switching layer and a second active resistance switching layer, with both active switching layers connected to electrode layers directly or through additional buffer layers between the active resistance switching layers and the electrodes. This device in its simplest form has the structure: electrode-active layer-buffer layer-active layer-electrode. The second active resistance switching layer may, in the alternative, be an ion donating layer, such that the structure becomes: electrode-active layer-buffer layer-ion donating layer-electrode. The EPIR device is constructed to mitigate the retention challenge.

Methods of using a two terminal multi-layer thin film resistance switching device with a diffusion barrier

Two terminal multi-layer thin film resistance switching device with a diffusion barrier and methods thereof

A switchable resistive device has a multi-layer thin film structure interposed between an upper conductive electrode and a lower conductive electrode. The multi-layer thin film structure comprises a perovskite layer with one buffer layer on one side of the perovskite layer, or a perovskite layer with buffer layers on both sides of the perovskite layer. Reversible resistance changes are induced in the device under applied electrical pulses. The resistance changes of the device are retained after applied electric pulses. The selected duration of the electrical pulse is in the range of from about 8 nanosecond to about 100 milliseconds. The selected maximum value of the electrical pulse is in the range of from about 1 V to about 150 V. The electrical pulse may have square, saw-toothed, triangular, sine, oscillating or other waveforms, and may be of positive or negative polarity.

Method of using a buffered electric pulse induced resistance device

A switchable resistive device has a multi-layer thin film structure interposed between an upper conductive electrode and a lower conductive electrode. The multi-layer thin film structure comprises a perovskite layer with one buffer layer on one side of the perovskite layer, or a perovskite layer with buffer layers on both sides of the perovskite layer. Reversible resistance changes are induced in the device under applied electrical pulses. The resistance changes of the device are retained after applied electric pulses. The functions of the buffer layer(s) added to the device include magnification of the resistance switching region, reduction of the pulse voltage needed to switch the device, protection of the device from being damaged by a large pulse shock, improvement of the temperature and radiation properties, and increased stability of the device allowing for multivalued memory applications.

Switchable two terminal multi-layer perovskite thin film resistive device and methods thereof

Method of using a switchable resistive perovskite microelectronic device with multi-layer thin film structure

Switchable resistive perovskite microelectronic device with multi-layer thin film structure

A thin film solid oxide fuel cell (TFSOFC) having a porous metallic anode and a porous cathode is provided. The fuel cell is formed by using a continuous metal foil as a substrate onto which is deposited a thin anode metal layer which is then patterned to reveal an array of pores in the anode. A dense thin film electrolyte is then deposited onto the porous anode layer overcoating the anode and filling the anode pores. The substrate foil layer is then removed to allow for exposure of the porous anode/electrolyte to fuel. The cathode is then formed on the electrolyte by depositing a cathode thin film cap using known film deposition techniques. Further processing may be used to increase the porosity of the electrodes. The metal foil may be treated to have an atomically ordered surface, which makes possible an atomically ordered anode and atomically ordered thin film electrolyte for improved performance.

Thin film solid oxide fuel cell with lithographically patterned electrolyte and anode layers

A basic form of a variable capacitive apparatus and its actuating method are disclosed. The apparatus is a simple two-terminal structure and may be set by short duration, low voltage electrical pulses. Materials with perovskite structure or perovskite-related structures, especially colossal magnetoresistive materials, are the active constituents of the apparatus. The apparatus overcomes the shortcomings of its predecessors and offers the advantages of non-volatility, two or multi-level storage, non-destructive reading, free-of-power maintenance and potential high radiation hardness.

Electrically programmable nonvolatile variable capacitor

A thin film solid oxide fuel cell (TFSOFC) having a porous metallic anode and a porous cathode is provided. The fuel cell is formed by using a continuous metal foil as a substrate to epitaxially deposit a thin film electrolyte on one surface of the foil. The metal foil may then be made porous by photolithographically patterning and etching the other surface of the foil to form holes extending through the foil to the electrolyte/foil interface. The cathode is then formed on the electrolyte by depositing a second thin film using known film deposition techniques. Further processing may be used to increase the porosity of the electrodes. The metal foil may be treated before film deposition to have an atomically ordered surface, which makes possible an atomically ordered thin film electrolyte.

Thin film solid oxide fuel cell and method for forming

A method for switching properties of perovskite thin film materials, including the colossal magnetoresitive (CMR) and high temperature superconducting (HTSC) materials, is provided. Short electrical pulses are applied to the materials in thin films to change both reversibly and non-reversibly the electrical, thermal, mechanical and magnetic properties of the material. Reversible resistance changes of over a factor of 10 are induced in CMR materials at room temperature and in zero external magnetic field by electrical pulsing. Applications of the method and materials to form memory devices, resistors in electronic circuits which can be varied in resistance and other applications are disclosed.

Method for switching the properties of perovskite materials used in thin film resistors

A birefringence polarizing beam-splitter is provided. A series of periodic blazed grooves or grooves with echelon profile having a number of steps is provided on the surface of an optically birefringent material. The birefringent substrate material may be crystalline or plastic. In another embodiment, two substrates of birefringent material having a series of periodic blazed grooves or grooves with echelon profile are combined to achieve greater angle of beam splitting.

Birefringent grating polarizing beam splitter

A method for treating retinal damage by implanting a thin film optical detector based on a dielectric capacitor. When illuminated, the dielectric capacitor generates an electrical field that replaces signals from damaged retinal photoreceptors in the eye. The generated electric field stimulates healthy local nerve endings and are perceived by the patient as light. In a preferred embodiment, the detectors are implanted onto the retina in groups to provide spatial resolution.

Growing community of inventors

Houston, TX, United States of America

Naijuan Wu