scholarly journals Physical Investigations on Bias-Free, Photo-Induced Hall Sensors Based on Pt/GaAs and Pt/Si Schottky Junctions

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3009
Author(s):  
Xiaolei Wang ◽  
Xupeng Sun ◽  
Shuainan Cui ◽  
Qianqian Yang ◽  
Tianrui Zhai ◽  
...  
Keyword(s):  
Barrier Height ◽  
Schottky Contact ◽  
Surface States ◽  
Open Circuit ◽  
Electrical Characteristics ◽  
Hall Voltage ◽  
Novel Structure ◽  
Hall Effects ◽  
Schottky Junctions ◽  
Hall Sensors

Hall-effect in semiconductors has wide applications for magnetic field sensing. Yet, a standard Hall sensor retains two problems: its linearity is affected by the non-uniformity of the current distribution; the sensitivity is bias-dependent, with linearity decreasing with increasing bias current. In order to improve the performance, we here propose a novel structure which realizes bias-free, photo-induced Hall sensors. The system consists of a semi-transparent metal Pt and a semiconductor Si or GaAs to form a Schottky contact. We systematically compared the photo-induced Schottky behaviors and Hall effects without net current flowing, depending on various magnetic fields, light intensities and wavelengths of Pt/GaAs and Pt/Si junctions. The electrical characteristics of the Schottky photo-diodes were fitted to obtain the barrier height as a function of light intensity. We show that the open-circuit Hall voltage of Pt/GaAs junction is orders of magnitude lower than that of Pt/Si, and the barrier height of GaAs is smaller. It should be attributed to the surface states in GaAs which block the carrier drifting. This work not only realizes the physical investigations of photo-induced Hall effects in Pt/GaAs and Pt/Si Schottky junctions, but also opens a new pathway for bias-free magnetic sensing with high linearity and sensitivity comparing to commercial Hall-sensors.

NITRIDE BASED SCHOTTKY-BARRIER PHOTOVOLTAIC DEVICES

2007 ◽  
Vol 1040 ◽  
Author(s):  
Balakrishnam R Jampana ◽  
Omkar K Jani ◽  
Hongbo Yu ◽  
Ian T Ferguson ◽  
Brian E McCandless ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Annealing Temperature ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Schottky Contact ◽  
Open Circuit ◽  
Photovoltaic Devices ◽  
Current Increase ◽  
Uv Illumination

AbstractSchottky-barrier photovoltaic devices are fabricated by selective metal deposition on p-GaN. A 1.25 V open-circuit voltage is observed for the best device. Devices were optimized by annealing in forming gas at temperatures ranging from 550°C to 700°C. Annealing time and forming gas flow rate are used to control the metal-semiconductor Schottky barrier formation. Optimum fabrication parameters are achieved based on photovoltaic response from the devices under UV illumination. Barrier heights (0.47 eV - 0.49 eV) were used as basis to compare the device response. The Schottky-barrier height is very sensitive to processing conditions, for example a 2.5% increase in barrier height is observed when Schottky contact annealing temperature is changed from 600 °C to 650 °C. Under UV illumination, the open-circuit voltage and short-circuit current increase with increasing annealing temperature while the series resistance decreases under such conditions.

Electrical Characteristics of Pt Schottky Contact to Semipolar (11-22) n-GaN Depending on Si Doping Concentration

2013 ◽  
Vol 404 ◽  
pp. 146-151
Author(s):  
Sung Min Jung ◽  
Kyoung Kook Kim ◽  
Sung Nam Lee ◽  
Hyun Soo Kim
Keyword(s):  
Carrier Transport ◽  
Doping Concentration ◽  
Schottky Diodes ◽  
Schottky Contact ◽  
Surface States ◽  
Incident Beam ◽  
Electrical Characteristics ◽  
X Ray ◽  
Si Doping ◽  
Thermionic Field Emission

Electrical characteristics of Pt Schottky contact formed on semipolar (11-22) n-type GaN planes with different Si doping concentration were investigated. Large Si doping to semipolar (11-22) n-GaN led to improved electrical and structural properties, e.g., the Hall mobility (μ) was increased by 35 % and the full width at half maximum (FWHM) of X-ray rocking curves with X-ray incident beam direction of [-1-12 was decreased by 34 %. Thermionic field emission (TFE) theory applied to the forward current-voltage (I-V) curves of fabricated Pt Schottky diodes yielded the Schottky barrier height (ΦB) of 1.64 and 1.84 eV, the tunneling parameter (E00) of 44 and 65 meV, and the ideality factor (n) of 1.83 and 2.57 for the lowly doped and highly doped samples, respectively, indicating that the Si doping affected the carrier transport properties substantially associated with the change of surface states density.

Theory of injection photovoltages in organic insulators

1976 ◽  
Vol 29 (10) ◽  
pp. 2123 ◽  
Author(s):  
JS Bonham
Keyword(s):  
Light Intensity ◽  
Surface States ◽  
Threshold Value ◽  
High Light Intensity ◽  
Open Circuit ◽  
Charge Carriers ◽  
Single Carrier ◽  
Injection Mechanism ◽  
Wavelength Variation ◽  
Open Circuit Photovoltage

Development of an open-circuit photovoltage, U, in an organic insulator by photoinjection of charge carriers from the electrodes is treated theoretically. In the single-carrier case (both electrodes injecting the same carrier) it is shown that, in the absence of surface traps, U increases at a rate of 60 mV per decade of light intensity, II, above a threshold value of II. Photoinjection from the back (unilluminated) electrode by incompletely absorbed light causes U to become independent of ll at high light intensity. The same process may also cause U to change sign as the wavelength approaches an absorption minimum of the organic. Traps in the bulk of the insulator do not affect the single-carrier photovoltage, but traps at the surface may complicate the intensity dependence of U if they are involved in the injection mechanism. They may for example cause U to decrease and change sign at high n. Only shallow surface traps are considered. Possible effects of surface states are discussed briefly. The major assumption of this paper--neglect of all but injected charge carriers-breaks down in principle in the two-carrier case. However, if there are no sources of photovaltage in the bulk of the insulator the two-carrier case gives a stronger dependence of U on II, and no saturation or possibility of change of sign with wavelength variation. Predictions of the model are shown to agree with the results for a number of systems reported in the literature.

Schottky contact barrier height extraction by admittance measurement

2007 ◽  
Vol 101 (5) ◽  
pp. 053705 ◽  
Author(s):  
Yu-Long Jiang ◽  
Jia Luo ◽  
Ye Yao ◽  
Fang Lu ◽  
Guo-Ping Ru ◽  
...  
Keyword(s):  
Barrier Height ◽  
Schottky Contact ◽  
Contact Barrier ◽  
Admittance Measurement

scholarly journals Investigation of Radiation Effects on FD-SOI Hall Sensors by TCAD Simulations

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3946
Author(s):  
Linjie Fan ◽  
Jinshun Bi ◽  
Kai Xi ◽  
Gangping Yan
Keyword(s):  
Computer Aided Design ◽  
Radiation Effects ◽  
Heavy Ion ◽  
Silicon On Insulator ◽  
Voltage Sensitivity ◽  
Hall Voltage ◽  
Fully Depleted ◽  
Offset Voltage ◽  
Hall Sensors ◽  
Tcad Simulations

This work investigates the responses of the fully-depleted silicon-on-insulator (FD-SOI) Hall sensors to the three main types of irradiation ionization effects, including the total ionizing dose (TID), transient dose rate (TDR), and single event transient (SET) effects. Via 3D technology computer aided design (TCAD) simulations with insulator fixed charge, radiation, heavy ion, and galvanomagnetic transport models, the performances of the transient current, Hall voltage, sensitivity, efficiency, and offset voltage have been evaluated. For the TID effect, the Hall voltage and sensitivity of the sensor increase after irradiation, while the efficiency and offset voltage decrease. As for TDR and SET effects, when the energy deposited on the sensor during a nuclear explosion or heavy ion injection is small, the transient Hall voltage of the off-state sensor first decreases and then returns to the initial value. However, if the energy deposition is large, the transient Hall voltage first decreases, then increases to a peak value and decreases to a fixed value. The physical mechanisms that produce different trends in the transient Hall voltage have been analyzed in detail.

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