Applications of a-Si:H radiation detectors

Fujieda, Ichiro; Cho, G.; Kaplan, S.N.; Perez‐Mendez, V.; Qureshi, S.; Street, R. A.

doi:10.1016/0022-3093(89)90396-7

Cited by 12 publications

(5 citation statements)

References 31 publications

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“…speed and signal yield 3 The decay constant of a scintillator can be obtained by analyzing the charge-sensitive preamplifier output wh~n . the scintillator coupled to a photodiode is irradiated by a short Xray pulse.…”

Section: Ill Characferistics Of Evaporated Csi(tl)mentioning

confidence: 99%

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X-ray and charged particle detection with CsI(Tl) layer coupled to a Si:H photodiode layers

Fujieda

Cho

Drewery

et al. 1991

IEEE Trans. Nucl. Sci.

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Section: Ill Characferistics Of Evaporated Csi(tl)mentioning

confidence: 99%

“…Not to be taken from this room H has been investigated as a possible alternative for radiation detector material for high energy physics experiments, medical imaging, material and life science studies [1,2,3]. Early efforts to make X-ray detectors with a-Si:H by Wei et al [4] used a phosphor such as CdW04 and ZnS(Ni).…”

Section: ---------------October 1990mentioning

confidence: 99%

X-ray and charged particle detection with CsI(Tl) layer coupled to a Si:H photodiode layers

Fujieda

Cho

Drewery

et al. 1991

IEEE Trans. Nucl. Sci.

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“…Although amorphous hydrogenated silicon (a‐Si:H) is one of the most well‐studied semiconductor systems and finds practical applications in a diverse array of devices including photovoltaics, [ 1–3 ] radiation detectors, [ 4–6 ] and thin‐film transistors, [ 7–9 ] a detailed understanding of the dynamics of photogenerated charge carriers has remained incomplete due to the complexity of the microscopic landscape of amorphous systems. The band structure formalism that leads to accurate descriptions of well‐ordered crystalline semiconductors fails to adequately describe the behavior of amorphous systems, which are characterized by an exponentially decaying density of states in energies that extend into the classically forbidden band gap (see Figure a).…”

Section: Introductionmentioning

confidence: 99%

Study of Photocarriers Lifetime Distribution in a‐Si:H via Magneto‐photoconductivity and Magneto‐Photoluminescence

McLaughlin

Pan

Sun

et al. 2022

Advanced Optical Materials

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a detailed understanding of the dynamics of photogenerated charge carriers has remained incomplete due to the complexity of the microscopic landscape of amorphous systems. The band structure formalism that leads to accurate descriptions of well-ordered crystalline semiconductors fails to adequately describe the behavior of amorphous systems, which are characterized by an exponentially decaying density of states in energies that extend into the classically forbidden band gap (see Figure 1a). Due to this large density of native defects and mid-gap states such as dangling bonds (DBs, see Figure 1a), the dynamics of photogenerated carriers in a-Si:H resemble to those of organic semiconductors, where the charge transport may also occur by hopping between nearby localized states having similar carrier mobility values. Also radiative recombination occurs between localized, strongly exchange-coupled electron-hole (e-h) polaron pairs. In addition, the photogenerated carriers are similarly localized in both systems. For these reasons, there might be valuable insight to be gained by applying some of the models of spin-dependent recombination processes developed in the field of organic semiconductors [10][11][12] to the a-Si:H system, as done here.It is an experimentally challenging task to probe photocarriers in an energy-resolved manner so that the effects of wavefunction localization in such amorphous systems might be elucidated. Magnetic resonance experiments can be devised so that only a desired subset of the total photogenerated carrier population is probed. [13] For example, electrically detected magnetic resonance [14] is sensitive only to those carriers which participate in conduction, so that the g-factors and hyperfine coupling strengths of electrons or holes near their respective mobility edges may be revealed. Optically detected magnetic resonance [15][16][17] and light-induced electron spin resonance [18] are sensitive to localized spin ½ electrons or holes that are trapped in deep defect states and do not participate in transport. Powerful as these techniques are for probing the local environment of photogenerated charge carriers, it is desirable to supplement them by a careful investigation of the steady-state photoluminescence (PL) and photocurrent (PC) efficiency, so that practical a-Si:H devices operating in the steady-state regime may benefit from the thorough understanding of microscopic carriers dynamics.Herein, the magneto-photoluminescence (MPL) of localized photocarriers and magneto-photoconductivity (MPC) of delocalized photocarriers in amorphous hydrogenated silicon (a-Si:H) films and devices, respectively, are investigated. Both responses are caused by mixing of spin sublevels in the photogenerated electron-hole (e-h) pairs that alters their recombination and dissociation rates. The spin mixing occurs by a combination of hyperfine interaction (HFI) between spin ½ photocarriers and neighboring 29 Si and 1 H nuclei, and the Δg mechanism which originates from a difference in the Landé g-factors of el...

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“…For a long time, silver emulsion films has been used to capture X-ray images. In 1988, an amorphous silicon TFT based 2-D X-ray image sensor was proposed first by a Berkeley group [1]. Then in 1990, a slot scan (1-D) system using Charge Coupled Device (CCD) was launched as the first commercial digital device.…”

Section: Introductionmentioning

confidence: 99%

Development of a 55 μmpitch 8 inch CMOS image sensor for the high resolution NDT application

Kim

Cho

et al. 2016

J. Inst.

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A: A CMOS image sensor (CIS) with a large area for the high resolution X-ray imaging was designed. The sensor has an active area of 125 × 125 mm 2 comprised with 2304 × 2304 pixels and a pixel size of 55 × 55 µm 2 . First batch samples were fabricated by using an 8 inch silicon CMOS image sensor process with a stitching method. In order to evaluate the performance of the first batch samples, the electro-optical test and the X-ray test after coupling with an image intensifier screen were performed. The primary results showed that the performance of the manufactured sensors was limited by a large stray capacitance from the long path length between the analog multiplexer on the chip and the bank ADC on the data acquisition board. The measured speed and dynamic range were limited up to 12 frame per sec and 55 dB respectively, but other parameters such as the MTF, NNPS and DQE showed a good result as designed. Based on this study, the new X-ray CIS with ∼50 µm pitch and ∼150 cm 2 active area are going to be designed for the high resolution X-ray NDT equipment for semiconductor and PCB inspections etc.

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Applications of a-Si:H radiation detectors

Cited by 12 publications

References 31 publications

X-ray and charged particle detection with CsI(Tl) layer coupled to a Si:H photodiode layers

X-ray and charged particle detection with CsI(Tl) layer coupled to a Si:H photodiode layers

Study of Photocarriers Lifetime Distribution in a‐Si:H via Magneto‐photoconductivity and Magneto‐Photoluminescence

Development of a 55 μmpitch 8 inch CMOS image sensor for the high resolution NDT application

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