Counter diode

The FF also indicates the quality of the photodiode. Counter diode will lead to a negative curvature of the J-V curve in the fourth quadrant and reduce the FF below 25%. Large serial resistance and small parallel resistance can also reduce the FF. In addition, high FF value requires a photovoltaic device with a strict selection... 

Some properties of the detectors most commonly used for transmission experiments are summarized in Table 3.2. Alternative counters are scintillation detectors based on Nal or plastic material that is attached to a photomultiplier, and solid-state detectors using silicon- or germanium-diodes. 

Solid-state detectors based on silicon- or germanium-diodes possess better resolution than gas counters, particularly when cooled with liquid nitrogen, but they allow only very low count rates. PIN diodes have also recently become available and have been developed for the instruments used in the examination of Martian soils (Sects. 3.3 and 8.3). A very recent development is the so-called silicon-drift detector (SDD), which has very high energy resolution (up to ca. 130 eV) and large sensitive detection area (up to ca. 1 cm ). The SNR is improved by an order of magnitude compared to Si-PIN detectors. Silicon drift detectors may also be used in X-ray florescence spectroscopy, even in direct combination with Mossbauer spectroscopy (see Sects. 3.3 and 8.3). 

The 99 keV y-quanta are usually counted with Nal(Tl) scintillation counters or Ge(Li) diodes in transmission geometry. A Cd absorber should be used to reduce the background counting rate of the K X-rays and to avoid pile-up of the different X- and y-rays (cf. Fig. 4 in [325]). 

Sayre, E. V. (1965). Refinement in methods of neutron activation analysis of ancient glass objects through the use of lithium drifted germanium diode counters. In Comptes Rendus Vile Congres International du Verre, Bruxelles, 28 Juin-3 Juillet 1965, Charleroi, Institut National du Verre. 

Since both metals and degenerate semiconductors have been used as the counter-electrode to the semiconductor in both diode and capacitor-type devices, a more general notation than that usually found in the literature will be employed in this review. This more generalized notation will refer to the counter-electrode as the conductor (c). Hence, M-S, M-I-S, and degenerate semiconductor-interfacial layer-semiconductor diode devices all become C-S or C-I-S... 

Modifications to the experimental set-up for the acquisition of fluorescence spectra from samples within the ESR microwave cavity are described in previous work ( ). Further improvements using a fast photomultiplier/photon counting technique were made in an attempt to determine the radiative fluorescence lifetime in solution. Phosphorescence at 77 K was measured both by a conventional Varian spectrofluorimeter and a pulsed laser/cooled diode array imaging device. Radiative phosphorescence lifetimes were measured by the photon counting technique, using the Stanford Research System SR400 gated photon counter. 

Fig. 6.13. Anodic current vs. potential curves for the process of BH4 ions oxidation on the bulk Cu electrode (curve 1 for comparison see curve 2 registered in the same conditions without BH4 ions), on the initial Ti02 electrodes (curve 7 for Ti02 with Nd = 10 19 cm 3 curve 8 for Ti02 with Nd 1018 cm 3) and on the Ti02 electrodes surface modified with different concentration of Cu (curve 3 - 1018 atoms/cm2, curves 4,5 - 1016 atoms/cm2, curve 6 - 1015 atoms/cm2). The values of Nd for Ti02 were 1018 cm 3 (curve 5) and 1019 cm 3 (curves 3,4,6). Curve 9 was obtained with the use of represented electrical circuit modeling the system Ti02 - Cu particles - electrolyte (D - solid-state Schottky diode R - electrical resistor WE, RE and CE - working, reference and counter electrodes, correspondingly). Electrolyte 0.1 M NaBH4 + 0.1 M NaOH. The potential sweep rate is 5 mV/s.

Alpha-particle detector Beta-particle detector Gamma-ray detector proportional counters silicon (Si) diode with spectrometer proportional counters Geiger-Muller counters liquid scintillation (LS) counters thallium-activated sodium iodide (Nal(Tl) detector with spectrometer germanium (Ge) detector with spectrometer... 

In extension to this frequency chain we installed an optical frequency interval divider [23] to extrapolate to 1064 nm (see Fig. 3). The center frequency of the optical divider stage is given by the Nd YAG laser at 946 nm laser with its frequency determined via the beat note with the comb locked laser diode at 946 nm. The higher input frequency of the divider stage is set by a diode laser at 852 nm which is heterodyned with another diode laser at 852 nm, also phase locked to the frequency comb. The lower input frequency of the divider stage is determined by the iodine stabilized Nd YAG laser at 1064 nm. While scanning the frequency doubled 1064 nm Nd YAG laser over the iodine line the two beat notes at 852 nm and 946 nm are measured with a rf-counter. They are then used to determine the absolute frequency of the 1064 nm Nd YAG laser. 

The rapid development of solid-state electronic devices in the last two decades has had a profound effect on measurement capabilities in chemistry and other scientific fields. In this chapter we consider some of the physical aspects of the construction and function of electronic components such as resistors, capacitors, inductors, diodes, and transistors. The integration of these into small operational amplifier circuits is discussed, and various measurement applications are described. The use of these circuit elements in analog-to-digital converters and digital multimeters is emphasized in this chapter, but modern integrated circuits (ICs) have also greatly improved the capabilities of oscilloscopes, frequency counters, and other electronic instruments discussed in Chapter XIX. Finally, the use of potentiometers and bridge circuits, employed in a number of experiments in this text, is covered in the present chapter. 

In principle, photoelectrochemical cells can be used for the conversion of solar energy into electrical energy or for the production of a storable fuel. The first type (regenerative cells) consists of a semiconductor and inert counter electrode and a redox system in the electrolyte. The current-voltage behaviour is described by the diode equation, which is also valid for pure solid state devices (pn-junction, Schottky diode) i.e. 

Hiac PC4000 portable liquid particle counter is a contamination measurement tool, designed to run on-line analyses of hydraulic systems and fluids. The fully self-contained counter operates in the light-blocking mode using a laser diode and reports contamination levels at 4, 6, 10, 14, 21,38 and 70 pm at a flow rate of 60 ml min. ... 

Hiac 8012 liquid particle counting system analyzes viscous, dark, dirty fluids without dilution. The system includes the Hiac SDS (syringe driven sampler), 8000A counter and an HRLD (Hiac/Royco laser diode) sensor. 

Pacific Scientific Met One 210 Liquid Particle Counter is used to measure particles in clean fluids used in electronic, pharmaceutical and other manufacturing processes. It classifies particles in six size ranges in the 0.4 to 25 pm size range using laser diode based forward light scattering. Maximum count rate is 8000 particles per minute at a fluid flow rate of 100 ml min. ... 

Optical trapping by two counter propagating diode laser beams 1,070 nm, Raman 785 nm through microscope objective HK60 human promyelocytic leukemia cells Cytoplasm 643, 852, 939, 1,660 cm nucleus. A, T, G, and C at 785, 830,895,1,048,1,093 cm and thymine at 751 cm Nucleus, cytoplasm, and membrane are distinguished in one cell... 

In a conventional single crystal or polycrystalline photoelectrochemical cells, the difference between the Fermi level of the semiconductor electrode and the counter electrode is expected to follow a logarithmic relationship with the light intensity described by the diode equation [160]. An analog of the diode equation for dye-sensitized cells can be obtained by equating the recombination rate to the injection flux under open-circuit conditions, Eq. 34 ... 

Figure 12.8 The two mtegories of detectors used for energy dispersive X-ray fluorescence spectrometry. (a) Proportional counter used in pulse mode (b) Cooled Si/Li diode detector using Peltier effect (XR detector by Amptek Inc.) (c) Functioning principle of a scintillation detector containing a large size reverse polarized semi-conductor crystal. Each incident photon generates a variable number of electron-hole pairs. The very high quantum yield enables the use of low power primary sources of X-rays (a few watts or radio-isotopic sources).

The semi-conductor transducer (scintillation counter). Each X-ray photon increases the conductivity of the active zone (the junction) of a lithium-doped silicon diode (one electron for around 3.6 eV). The background noise is reduced if the sensor is maintained at low temperature (cooled by liquid nitrogen or a Peltier device). The entry surface is protected by a beryllium film of a few pm (transparent for Z > 11) (Figure 12.8). In one or other cases the impulse furnished by the detector allows to go back to the energy of the incident photon. 

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