common emitter

A wide range of emitter composition, thickness, and doping is studied via dc current gain measurements on large area GaAs based heterojunction bipolar transistors (HBTs) at both room and elevated temperatures. InGaP emitters offer the widest thickness and doping design window in terms of dc peak current gain, as compared with AlGaAs emitters. Remarkably, a 50 Å InGaP emitter HBT retains 50% gain of a more standard 500 Å emitter device. For state-of-the-art HBTs, a degraded peak gain is argued to be caused by an increased reverse hole injection current (IRHI). In light of previously published results which implicate IRHI as a mechanism for materials limited HBT reliability, we suggest dc current gain measurements on large-area HBTs give meaningful insights into the long term reliability of the structure. Specifically, the wider emitter thickness and doping design window offered by an InGaP emitter HBT could apply to reliability as well as to the demonstrated gain stability.

Laser-assisted diffusion of phosphorus dopants has been investigated to realize selective emitters on mc-Si wafers. In this paper, we studied, in the presence of PSG, the effect of laser speed and power doping parameters on the sheet resistance RSq variation as a function of selective emitter formation. Four point-probe (FPP) measurements showed that 5.5–10 W with speed 100–1500 mm s−1 are, respectively, the best power values to form a selective emitter with 20–40 Ω/□ typical values. Electrochemical Capacitance-Voltage (ECV) results showed that dopant concentration and junction depth increased with decreasing scan speed, resulting in lower sheet resistances. Thus, the greater the difference between the concentration of starting phosphorus and that created by laser treatment, the smaller the square RSq will be. Scanning Electron Microscopy (SEM) images demonstrated more pronounced patterns of laser ablation when the power is high and/or the scanning speed is low.

In this work we showcase the emitter DICzTRZ in which we employed a twin-emitter design of our previously reported material, ICzTRZ. This new system presented a red-shifted emission at 488 nm compared to that of ICzTRZ at 475 nm and showed a comparable photoluminescence quantum yield of 57.1% in a 20 wt % CzSi film versus 63.3% for ICzTRZ. The emitter was then incorporated within a solution-processed organic light-emitting diode that showed a maximum external quantum efficiency of 8.4%, with Commission Internationale de l’Éclairage coordinate of (0.22, 0.47), at 1 mA cm−2.

We report a metal oxide semiconductor field effect transistor (MOSFET) controlled field emission array (FEA) device. The device uses a lateral double diffused MOSFET (LD-MOSFET) to control electron supply to the surface. The FEAs were fabricated using isotropic etch of silicon, oxidation sharpening and chemical mechanical polishing. The LD-MOSFETs have a threshold voltage of 0.48V while the FEAs have a turn-on voltage of 28V. Analysis using the FN formulation indicates that a silicon tip radius of 11 nm would fit the FEA IV data. The tip radius from the electrical data is very close to the average tip radius of 10 nm obtained from transmission electron microscope (TEM) analysis. The IV characterization of the MOSFET/FEA demonstrated control of electron emission by the MOSFET gate voltage.

ABSTRACT: The experiment was carried out in one of the greenhouses in the Research station, Kirkuk University in 2017-2018 to evaluate and comparative two types of emitters GR and Turbo with two types of Cucumber Bark and Ameer, and there effective on indicators of quality irrigation operation, vegetative growth and the yield for the plant. The emitter indicators were analyzed by using T-test to compare emitters. There were no significant differences in all the indicators except the field emission uniformity and the absolute field emission uniformity, where the GR emitter with the Bark cultivar was 93% and 89% in uniformity of distribution, and absolute distribution uniformity was 92.8% and 90%, respectively, for two emitters. The GR emitter was higher on Turbo emitter with Ameer cultivar where 90.13% and 86.5% in the field emission uniformity and the absolute field emission uniformity was 90.87% and 88.5% respectively for two emitters. In order to determine the effect of this on plant characteristics, the data were analyzed using the RCBD. The results showed that GR was superior to Bark in vegetative characteristics of plant length and number of leaves. The highest values were 140.71 cm and 24.84 leaves plant-1 respectively, and the yield characteristics of the total number of fruits and total yield, achieved the highest values were 23.07 fruit plant -1 and 16.42 ton ha-1, respectively. While the turbo recorded with the Ameer the lowest values of vegetative growth characteristics was 112.70 cm and 19.53 leaves plant-1 respectively, and in the characteristics of the yield was 18.80 fruit plant -1 and 13.08 tons ha-1, respectively.

A unified model for the nickel-silicon theoretical contact resistivity was computed, using a 0.6 eV Schottky barrier height, and compared to recent experimental data. This model was subsequently inserted in a classical cooptimization procedure. Numerical simulations were combined with analytical power losses equations to find out the effect of homogeneous emitter doping profile on an ideal lab-scale silicon solar cell. According to this work, an optimized emitter for plated contacts on a 10 μm wide nickel seed layer should have a junction depth ranging from 0.5 to 4 μm and a surface doping from 4 x 10 18 to 2 x 10 19 cm-3. This broad range allows getting more than 25.5 % and up to 25.9 % theoretical efficiency on a 2 x 2 cm² silicon solar cell metallized with 10 μm thick fingers. Finally, contour plots were also simulated using a larger Schottky barrier height in order to figure out the effect of the nickel silicide contact interface on solar cell properties.