Leland Stanford Junior University

University of California

Zhi-Xun Shen

Nicholas A Melosh

Zahid Hussain

Michael M Kelly

Wanli Yang

Jason D Fabbri

Zhengyu Wang

Michael A Kelly

Igor Bargatin

Jared W Schwede

Daniel Riley

Kunal Sahasrabuddhe

Keji Lai

The embodiments provide a thermionic emission device and a method for tuning a work function in a thermionic emission device is provided. The method includes illuminating an N type semiconductor material of a first member of a thermionic emission device, wherein a work function of the N type semiconductor material is lowered by the illuminating. The method includes collecting, on one of the first member or a second member of the thermionic emission device, electrons emitted from one of the first member or the second member.

Method for tuning work function using surface photovoltage and producing ultra-low-work-function surfaces, and devices operational therewith

Provided are electron emitters based upon diamondoid monolayers, preferably self-assembled higher diamondoid monolayers. High intensity electron emission has been demonstrated employing such diamondoid monolayers, particularly when the monolayers are comprised of higher diamondoids. The application of such diamondoid monolayers can alter the band structure of substrates, as well as emit monochromatic electrons, and the high intensity electron emissions can also greatly improve the efficiency of field-effect electron emitters as applied to industrial and commercial applications.

Diamondoid monolayers as electron emitters

A microwave microscope including a probe tip electrode vertically positionable over a sample and projecting downwardly from the end of a cantilever. A transmission line connecting the tip electrode to the electronic control system extends along the cantilever and is separated from a ground plane at the bottom of the cantilever by a dielectric layer. The probe tip may be vertically tapped near or at the sample surface at a low frequency and the microwave signal reflected from the tip/sample interaction is demodulated at the low frequency. Alternatively, a low-frequency electrical signal is also a non-linear electrical element associated with the probe tip to non-linearly interact with the applied microwave signal and the reflected non-linear microwave signal is detected at the low frequency. The non-linear element may be semiconductor junction formed near the apex of the probe tip or be an FET formed at the base of a semiconducting tip.

Modulated microwave microscopy and probes used therewith

A microwave imaging microscope and associated probe, or a read head. The probe or the read head includes a sensor unit with three fixed electrodes, preferably a stimulating electrode surrounding a sensing electrode and isolated by a grounded electrode. Circuitry couples the stimulating electrode to the probe signal variably selected in the range of 100 MHz to 100 GHz and couples the sensing electrode to a signal processor detecting in-phase and out-of-phase components of the current or voltage across the sensing electrode and the grounded electrode. A mechanical positioner moves the probe vertically towards the sample and scans it across the sample. The probe may be formed by semiconductor processing methods on a silicon chip.

Orthogonal microwave imaging probe

A non-resonant microwave imaging microscope and associated probe. The probe includes a sensor unit with two fixed electrodes, preferably a large outer electrode surrounding a small inner electrode which are approximately co-planar, thereby protecting the small inner electrode from an uneven topography. The outer electrode may be deposited on a conically shaped dielectric disk having a bore through which the inner electrode is placed. Non-resonant circuitry couples the inner electrode to the probe signal variably selected in the range of 10 MHz-50 GHz and to an amplifier whose output is coupled to a signal processor detector in-phase and out-of-phase components of the current or voltage across the two electrodes. A mechanical positioner moves the probe vertically towards the sample and scans it across the sample.

Non-resonant microwave imaging probe

Growing community of inventors

Stanford, CA, United States of America

Zhi-Xun Shen