We report on studies of electrical spin injection from ferromagnetic Fe contacts into semiconductor light emitting diodes containing single layers of InAs/GaAs self-assembled quantum dots QDs . An oblique magnetic field is used to manipulate the spin of the injected electrons in the semiconductor. This approach allows us to measure the injected steady-state spin polarization in the QDs, Pspin a...

A digital timing method aiming to minimize the time walk caused by the depth-dependent pulse shape variations in CdTe detectors has been developed. Detector pulses are digitized at the preamplifier stage and a full digital process is carried out to deduce and correct the time walk according to the interaction depth. A time resolution of 6.52 ns FWHM at an energy threshold of 150 keV with a CdTe...

We present parallel single molecule detection (SMD) and fluorescence correlation spectroscopy (FCS) experiments with a fully integrated complementary metal oxide semiconductor (CMOS) single-photon 2x2 detector array. Multifocal excitation is achieved with a diffractive optical element (DOE). Special emphasis is placed on parallelization of the total system. The performance of the novel single-p...

Mid-infrared detectors that are sensitive only in a tunable narrow spectral band are presented. They are based on the Resonant Cavity Enhanced Detector (RCED) principle and employing a thin active region using IV-VI narrow gap semiconductor layers. A Fabry-Pérot cavity is formed by two mirrors. The active layer is grown onto one mirror, while the second mirror can be displaced. This changes the...

Avalanche Photodiodes (APDs) connected with quenching circuits can be used for single photon detection. This semiconductor photon detector has a better performance than photomultiplier. The principles and applications of APDs are presented. Features, performance of different commercial devices are introduced and compared. Recent research progress based on the improvement of quenching circuits a...

Gamma-ray imaging with position-sensitive germanium detectors offers the advantages of excellent energy resolution, high detection efficiency, and potentially good spatial resolution. The development of the amorphous-semiconductor electrical contact technology for germanium detectors has simplified the production of these position-sensitive detectors and has made possible the use of unique dete...

A CMOS (complementary metal-oxide semiconductor) flatpanel X-ray detector is a two-dimensional silicon image sensor with a scintillator. We have tested the performance of two types of CMOS detectors in simultaneous small-angle/wideangle X-ray scattering experiments. Both are active-pixel devices that have an amplifier in each pixel. Wide-angle patterns were recorded with the detector just behin...

Solar-blind metal–semiconductor–metal (MSM) photodiodes based on MOCVD-grown Al0.6Ga0.4N template have been fabricated and tested. AlGaN detector samples were fabricated using a microwave compatible fabrication process. Optical transmission, current–voltage, spectral responsivity, and temporal pulse response measurements were carried out. The fabricated devices had very low leakage current and ...

Electron-electron interactions and detector bandwidth limit the maximal imaging speed of single-beam scanning electron microscopes. We use multiple electron beams in a single column and detect secondary electrons in parallel to increase the imaging speed by close to two orders of magnitude and demonstrate imaging for a variety of samples ranging from biological brain tissue to semiconductor waf...