We propose a hybrid device consisting of a graphene/silicon (Gr/Si) Schottky diode in parallel with a Gr/SiO2/Si capacitor for high-performance photodetection. The device, fabricated by transfer of commercial graphene on low-doped n-type Si substrate, achieves a photoresponse as high as 3 AW −1 and a normalized detectivity higher than 3.5 × 10 12 cmHz 1/2 W −1 in the visible range. The device exhibits a photocurrent exceeding the forward current, because photo-generated minority carriers, accumulated at Si/SiO2 interface of the Gr/SiO2/Si capacitor, diffuse to the Gr/Si junction. We show that the same mechanism, when due to thermally generated carriers, although usually neglected or disregarded, causes the increased leakage often measured in Gr/Si heterojunctions. At room temperature, we measure a zero-bias Schottky barrier height of 0.52 eV, as well as an effective Richardson constant A**=4 × 10 −5 Acm −2 K −2 and an ideality factor n ≈ 3.6, explained by a thin (< 1nm) oxide layer at the Gr/Si interface. 2

The imaging of integrated circuits across different length scales is required for failure analysis, design validation and quality control. Currently such inspection is accomplished using a hierarchy of different probes, from optical microscopy on the millimetre length scale to electron microscopy on the nanometre scale. Here we show that ptychographic X-ray laminography (PyXL) can provide non-destructive, three-dimensional views of integrated circuits, yielding both images of an entire chip volume and high-resolution images of arbitrarily chosen sub regions. We demonstrate the approach using chips produced with 16 nm fin field-effect transistor technology, achieving a reconstruction resolution of 18.9 nm, and compare our results to photolithographic mask layout files and more conventional imaging approaches such as scanning electron microscopy. The technique will also be applicable to other branches of science and engineering where three-dimensional X-ray images of planar samples are required.

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The dominant role of quantum fluctuations in determining the steady-state and transient response of a laser is demonstrated when there is a small number of particles in the system. In this regime, quantum fluctuations are found to suppress the lasing threshold and create a non-Poisson probability distribution for n discrete excited electronic states and s discrete photons. The correlation between n and s damps the averaged dynamic response of laser emission. Random walk calculations verify the master equation predictions and are used to connect to systems containing larger numbers of particles.

Electrical and mechanical engineers, materials scientists and applied physicists will find Levi's uniquely practical 2006 explanation of quantum mechanics invaluable. This updated and expanded edition of the bestselling original text covers quantization of angular momentum and quantum communication, and problems and additional references are included. Using real-world engineering examples to engage the reader, the author makes quantum mechanics accessible and relevant to the engineering student. Numerous illustrations, exercises, worked examples and problems are included; Matlab source codes to support the text are available from www.cambridge.org//9780521183994