Low Voltage High-Energy α-Particle Detectors by GaN-on-GaN Schottky Diodes with Record-High Charge Collection Efficiency

A low voltage (–20 V) operating high-energy (5.48 MeV) α-particle detector with a high charge collection efficiency (CCE) of approximately 65% was observed from the compensated (7.7 × 1014 /cm3) metalorganic vapor phase epitaxy (MOVPE) grown 15 µm thick drift layer gallium nitride (GaN) Schottky diodes on free-standing n+-GaN substrate. The observed CCE was 30% higher than the bulk GaN (400 µm)-based Schottky barrier diodes (SBD) at –20 V. This is the first report of α–particle detection at 5.48 MeV with a high CCE at –20 V operation. In addition, the detectors also exhibited a three-times smaller variation in CCE (0.12 %/V) with a change in bias conditions from –120 V to –20 V. The dramatic reduction in CCE variation with voltage and improved CCE was a result of the reduced charge carrier density (CCD) due to the compensation by Mg in the grown drift layer (DL), which resulted in the increased depletion width (DW) of the fabricated GaN SBDs. The SBDs also reached a CCE of approximately 96.7% at –300 V.

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Vertical GaN-on-GaN Schottky Diodes as α-Particle Radiation Sensors

Micromachines ◽

10.3390/mi11050519 ◽

2020 ◽

Vol 11 (5) ◽

pp. 519

Author(s):

Abhinay Sandupatla ◽

Subramaniam Arulkumaran ◽

Ng Geok Ing ◽

Shugo Nitta ◽

John Kennedy ◽

...

Keyword(s):

Collection Efficiency ◽

Schottky Diodes ◽

High Energy ◽

Hydride Vapor Phase Epitaxy ◽

Ultraviolet Rays ◽

Charge Carrier Density ◽

X Rays ◽

Free Standing ◽

Charge Collection Efficiency ◽

Radiation Sensors

Among the different semiconductors, GaN provides advantages over Si, SiC and GaAs in radiation hardness, resulting in researchers exploring the development of GaN-based radiation sensors to be used in particle physics, astronomic and nuclear science applications. Several reports have demonstrated the usefulness of GaN as an α-particle detector. Work in developing GaN-based radiation sensors are still evolving and GaN sensors have successfully detected α-particles, neutrons, ultraviolet rays, x-rays, electrons and γ-rays. This review elaborates on the design of a good radiation detector along with the state-of-the-art α-particle detectors using GaN. Successful improvement in the growth of GaN drift layers (DL) with 2 order of magnitude lower in charge carrier density (CCD) (7.6 × 1014/cm3) on low threading dislocation density (3.1 × 106/cm2) hydride vapor phase epitaxy (HVPE) grown free-standing GaN substrate, which helped ~3 orders of magnitude lower reverse leakage current (IR) with 3-times increase of reverse breakdown voltages. The highest reverse breakdown voltage of −2400 V was also realized from Schottky barrier diodes (SBDs) on a free-standing GaN substrate with 30 μm DL. The formation of thick depletion width (DW) with low CCD resulted in improving high-energy (5.48 MeV) α-particle detection with the charge collection efficiency (CCE) of 62% even at lower bias voltages (−20 V). The detectors also detected 5.48 MeV α-particle with CCE of 100% from SBDs with 30-μm DL at −750 V.

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Effect of the Depletion Region of a-Si:H Schottky Diodes on the Time-of-Flight Mobility-Lifetime Product

MRS Proceedings ◽

10.1557/proc-192-329 ◽

1990 ◽

Vol 192 ◽

Author(s):

N. Wyrsch ◽

P. Roca i Cabarrocas ◽

S. Wagner ◽

V. Viret

Keyword(s):

Collection Efficiency ◽

Schottky Diodes ◽

Time Of Flight ◽

Internal Field ◽

Laser Wavelength ◽

Depletion Region ◽

Charge Collection ◽

Charge Collection Efficiency ◽

Trapping Time ◽

Transient Photoconductivity

ABSTRACTThe effect of the depletion region in amorphous silicon Schottky diodes on the mobility-deep trapping lifetime product μτ of electrons has been investigated using transient photoconductivity techniques. We varied the laser wavelength of the exciting laser in time-of-flight (TOF) measurements. The results are correlated with measurements of the internal field by means of the charge collection efficiency, and with measurement of the deep-trapping time by the Delayed-Field TOF technique (DFTOF). We find that the electron μτ decreases from the bulk toward the top surface.

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Thin CVD diamond detectors with high charge collection efficiency

2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149) ◽

10.1109/nssmic.2000.949050 ◽

2002 ◽

Author(s):

A. Brambilla ◽

D. Tromson ◽

P. Bergonzo ◽

C. Mer ◽

F. Foulon

Keyword(s):

Collection Efficiency ◽

Cvd Diamond ◽

Charge Collection ◽

Charge Collection Efficiency ◽

High Charge

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Measurement of anomalously high charge collection efficiency in n+p strip detectors irradiated by up to 1016neq/cm2

Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment ◽

10.1016/j.nima.2009.01.207 ◽

2009 ◽

Vol 603 (3) ◽

pp. 263-267 ◽

Cited By ~ 33

Author(s):

Igor Mandić ◽

Vladimir Cindro ◽

Gregor Kramberger ◽

Marko Mikuž

Keyword(s):

Collection Efficiency ◽

Charge Collection ◽

Charge Collection Efficiency ◽

High Charge ◽

Strip Detectors

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Boosting charge collection efficiency via large-area free-standing Ag/ZnO core-shell nanowire array electrodes

Progress in Natural Science Materials International ◽

10.1016/j.pnsc.2019.03.002 ◽

2019 ◽

Vol 29 (2) ◽

pp. 124-128 ◽

Cited By ~ 2

Author(s):

Yuyi Feng ◽

Paul Kim ◽

Clayton A. Nemitz ◽

Kwang-Dae Kim ◽

Yoonseok Park ◽

...

Keyword(s):

Collection Efficiency ◽

Nanowire Array ◽

Charge Collection ◽

Core Shell ◽

Large Area ◽

Free Standing ◽

Charge Collection Efficiency

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Reasons for high charge collection efficiency of silicon detectors at HL-LHC fluences

Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment ◽

10.1016/j.nima.2018.08.034 ◽

2019 ◽

Vol 924 ◽

pp. 192-197 ◽

Cited By ~ 1

Author(s):

G. Kramberger

Keyword(s):

Collection Efficiency ◽

Charge Collection ◽

Silicon Detectors ◽

Charge Collection Efficiency ◽

High Charge

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EFFECT OF DEFECTS ORIGINATING UNDER THE PROTON IRRADIATION ON THE ELECTROPHYSICAL AND DETECTOR PROPERTIES OF CdTe:Cl AND CdZnTe

10.46813/2021-132-043 ◽

2021 ◽

pp. 43-50

Author(s):

A.I. Kondrik

Keyword(s):

Proton Irradiation ◽

Collection Efficiency ◽

Energy Levels ◽

Radiation Detectors ◽

High Energy ◽

Charge Collection ◽

Radiation Defects ◽

Initial State ◽

Charge Collection Efficiency ◽

Factors Affecting

The work is dedicated to studying by computer modeling the mechanisms of the influence of radiation defects, originating under high energy proton irradiation, on the resistivity ρ, lifetime of nonequilibrium electrons n and holes p in CdTe:Cl and Cd0.9Zn0.1Te, and charge collection efficiency η of room temperature ionizing radiation detectors based on these materials. The effect of recombination at deep levels of radiation defects on the degradation of n, p, and  of detectors based on CdTe:Cl and Cd0.9Zn0.1Te was studied. Energy levels of radiation defects also substantially effect on compensation degree of semiconductor decreasing ρ. The main factors affecting the abrupt or gradual decrease in the resistivity and charge collection efficiency of these detectors during their bombardment by high-energy protons, leading to complete degradation of their recording ability, were found. The important role of purity and deep donor concentration in initial state of the detector material was indicated.

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