Characterizations of Mesa Structural Near-Infrared n-Type Nanocrystalline-FeSi2/p-Type Si Heterojunction Photodiodes at Low Temperatures

2013 ◽  
Vol 747 ◽  
pp. 217-220 ◽  
Author(s):  
Nathaporn Promros ◽  
Ryūhei Iwasaki ◽  
Suguru Funasaki ◽  
Kyohei Yamashita ◽  
Tsuyoshi Yoshitake

In order to reduce the parasitic capacitance, mesa structural n-type NC-FeSi2/p-type Si heterojunctions were fabricated by photolithography. Their current-voltage characteristics were measured in the dark and under illumination using a 1.31 μm laser in the temperature range of 60 300 K. Their junction capacitance density was evidently reduced as compared with that of the normal structural diodes. The dark current was markedly reduced with a decrease in the temperature. At 60 K, a rectifying current ratio in the dark became more than five orders of magnitude at ±1V. The ratio of the photocurrent to the dark current was dramatically enhanced to be approximately two orders of magnitude, and the detectivity was calculated to be 1.5 × 1011 cmHz1/2/W at-1V. The obtained results showed a remarkable improvement in the device performance as compared with those at 300 K.

2015 ◽  
Vol 1103 ◽  
pp. 91-96
Author(s):  
Nathaporn Promros ◽  
Suguru Funasaki ◽  
Motoki Takahara ◽  
Ryūhei Iwasaki ◽  
Mahmoud Shaban ◽  
...  

Mesa structural n-type nanocrystalline-FeSi2/p-type Si heterojunctions were successfully fabricated by a lift-off technique combined with a photolithography process. Their current-voltage characteristics were measured at low temperatures range from 300 K down to 60 K. We estimated their diode parameters such as ideality factor, barrier height and series resistance based on the thermionic emission theory and Cheung’s method. From the estimation by the thermionic emission theory, the obtained results show an increase of ideality factor and a decrease of barrier height at low temperatures. The estimation by Cheung’s method shows that the values of ideality factor and barrier height are in agreement with those obtained from the thermionic emission theory. The obtained series resistances from dV/d (lnJ)-J and H(J)-J plots, which are approximately equal to each others, are increased at low temperatures.


2021 ◽  
Vol 21 (9) ◽  
pp. 4660-4664
Author(s):  
Woo-Seong Kim ◽  
Chan-Hyuk Ji ◽  
Se-Young Oh

We fabricated a photodetector device consisting of ITO/NiOx/Perovskite/PC60BM/BCP/Ag. The NiOx layer was deposited using the sol–gel and combustion processes. Combustion-processed NiOx films have advantages such as low annealing temperature, improved perovskite film quality, and better photodetector performance compared to the sol–gel processed NiOx film. The improved film quality, improved charge transfer, and reduced dark current of the device using combustion-processed NiOx film were investigated by measuring the current–voltage characteristics, transient photocurrent, and impedance analysis. The photodetector using the combustion-processed NiOx achieved a high detectivity of 1.20×1013 Jones and bandwidth of over 2 MHz at -0.1 V and 550 nm.


1999 ◽  
Vol 607 ◽  
Author(s):  
S. Kato ◽  
T. Horikoshi ◽  
T. Ohkubo ◽  
T. Iida ◽  
Y. Takano

AbstractThe bulk crystal of silicon germanium was grown by vertical Bridgman method with germanium composition, x, varying from 0.6 to 1.0. The temperature dependent variation of the mobility is indicative of alloy scattering dominantly for the bulk wafer. Phosphorus was diffused in as-grown p-type bulk wafer at 850 °C to form pn-junction, and the diffusion coefficient of phosphorus was evaluated as a function of x. The diffusion behavior of phosphorus in silicon germanium is closely correlated with the germanium self-diffusion with changing x. For specimens with lower content x, P concentration profiles indicated “kink and tail” shape, while it was not observed for higher x. For current-voltage characteristics measurement, an ideality factor was obtained.


2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Elisabeth A. Duijnstee ◽  
Vincent M. Le Corre ◽  
Michael B. Johnston ◽  
L. Jan Anton Koster ◽  
Jongchul Lim ◽  
...  

1985 ◽  
Vol 132 (2) ◽  
pp. 346-349 ◽  
Author(s):  
Nobuyoshi Koshida ◽  
Masahiro Nagasu ◽  
Takashi Sakusabe ◽  
Yuji Kiuchi

2013 ◽  
Vol 1562 ◽  
Author(s):  
Takehide Miyazaki ◽  
Hisao Nakamura ◽  
Kengo Nishio ◽  
Hisashi Shima ◽  
Hiroyuki Akinaga ◽  
...  

ABSTRACTWe present results of first-principles non-equilibrium Green’s function calculations for current-voltage (IV) characteristics of the electrode/HfO2/electrode model systems. In order to investigate the effect of the electrode materials on the IV characteristics, we considered two transition metals for electrode, Ta and W, which are both body-centered-cubic elemental metals but have different valence numbers. We simulated the ON state by placing oxygen vacancies in the HfO2 layer while the OFF state was modeled with HfO2 without oxygen vacancies. At the OFF state, no electric current flowed for -1 V up to +1 V, as expected. At the ON state, however, we found that the absolute current for the Ta electrode was twice as large as that for the W electrode. The analysis of the IV characteristics shows that the electronic coupling between Ta and HfO2 is substantially stronger than that between W and HfO2. Our study demonstrates the importance of the matching between electrode and insulator materials to achieve a high ON- to OFF-current ratio in ReRAMs at a low bias.


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