J. M. R. Weaver

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Channel temperature has a strong impact on the performance of a microwave power transistor. In particular, it has a strong influence on the power gain, energetic efficiency, and reliability of the device. The thermal optimization of device geometry is therefore a key issue, together with precise measurements of temperature within the channel area. In this(More)
Since its introduction, SECM-AFM has gained recognition as an extremely useful tool for a wide variety of analytical and imaging applications. We have developed a probe fabrication method that uses single-walled carbon nanotube bundles as a structural template for the formation of a nanowire at the apex of an AFM tip. Subsequent insulation of the probe and(More)
Thermoelectric materials are one potential technology that could be used for energy harvesting. Here we report results from nanoscale Ge/SiGe heterostructure materials grown on Si substrates designed to enhance the thermoelectric performance at room temperature. The materials and devices are aimed at integrated energy harvesters for autonomous sensing(More)
A batch microfabricated scanning thermal microscopy (SThM) probe is presented. The sensor, based on a Pd resistance thermometer is shown to be suitable for calibration and stable for very long periods (> 700 hours). A technique for achieving transformer isolation of the SThM probe is described and shown to be a highly effective route to obtaining(More)
This study has demonstrated that the thermal conductivity of small samples of highly thermally conductive materials can be accurately measured using scanning thermal microscopy (SThM) when calibrated using Johnson noise thermometry. A nanocrystalline diamond film sample was measured in two forms, membrane and film supported on a Si substrate. The results(More)
Thermoelectric materials are one potential technology that could be used for energy harvesting. Here we report results from nanoscale Ge/SiGe heterostructure materials grown on Si substrates designed to enhance the thermoelectric performance at room temperature. The materials and devices are aimed at integrated energy harvesters for autonomous sensing(More)
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