Photoconductivity in Materials Research

Brinza, Monica; Willekens, J; Benkhedir, M. L.; Adriaenssens, Guy

doi:10.1007/978-0-387-29185-7_7

Cited by 3 publications

(2 citation statements)

References 25 publications

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“…For the photoconductivity measurements a high-power UV LED with a dominant wavelength of 365 nm and with a typical output power of 360 mW was used. Excitation energy dependence, gain and decay time of the photocurrent were studied through photoconductivity spectroscopy, steady-state I-V and transient I-V measurements, respectively [24].…”

Section: Experimental Methodsmentioning

confidence: 99%

Radiation sensors based on GaN microwires

Verheij¹,

Peres²,

Cardoso³

et al. 2018

J. Phys. D: Appl. Phys.

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GaN microwires were shown to possess promising characteristics as building blocks for radiation resistant particle detectors. They were grown by metal organic vapour phase epitaxy with diameters between 1 and 2 μm and lengths around 20 μm. Devices were fabricated by depositing gold contacts at the extremities of the wires using photolithography. The response of these single wire radiation sensors was then studied under irradiation with 2 MeV protons. Severe degradation of the majority of devices only sets in for fluences above protons cm−2 revealing good radiation resistance. During proton irradiation, a clear albeit small current gain was observed with a corresponding decay time below 1 s. Photoconductivity measurements upon irradiation with UV light were carried out before and after the proton irradiation. Despite a relatively low gain, attributed to significant dark currents caused by a high dopant concentration, fast response times of a few seconds were achieved comparable to state-of-the-art GaN nanowire photodetectors. Irradiation and subsequent annealing resulted in an overall improvement of the devices regarding their response to UV radiation. The photocurrent gain increased compared to the values that were obtained prior to the irradiation, without compromising the decay times. The results indicate the possibility of using GaN microwires not only as UV detectors, but also as particle detectors.

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Section: Experimental Methodsmentioning

confidence: 99%

Radiation sensors based on GaN microwires

Verheij¹,

Peres²,

Cardoso³

et al. 2018

J. Phys. D: Appl. Phys.

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“…At least one of the contacts is made semi-transparent to allow free-carrier generation in the sample by means of a short, strongly absorbed light pulse. A pulsed laser is generally used for this purpose [23]. The best-known method of determination of the properties of minority carriers is to measure the diffusion length of the carriers.…”

Section: Introductionmentioning

confidence: 99%

Determination of the transport parameters of nanocrystalline CdSe:Cu thin films

Al-Kabbi¹,

Sharma²,

Saini³

et al. 2013

Phys. Scr.

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Thin films of copper (Cu)-doped CdSe are prepared by the physical vapor deposition technique. X-ray diffraction analysis shows that the films crystallize in hexagonal structure with (100) as the preferred orientation. Scanning electron microscope studies reveal that the grains are spherical in shape and uniformly distributed all over the surface of the substrates. The transport properties of Cu-doped CdSe thin films have been investigated by the time-of-flight measurement, steady-state photocarrier grating and steady-state photoconductivity techniques. The temperature dependence of dark conductivity and photoconductivity data reflects the existence of two independent donor energy levels. The bimolecular recombination nature of the thin films has been found from the photocurrent-illumination dependence at different applied voltages. The minority carrier diffusion length (L diff ) is obtained both from the best fit of the experimental photocurrent ratio β versus grating period ( ) and from the 'Balberg plot'. A straight line has been obtained from the best fit, which confirms that the measured length is the ambipolar diffusion length.

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Optical spectroscopy and band gap analysis of hybrid improper ferroelectric Ca3Ti2O7

Cherian

Birol

Harms

et al. 2016

Applied Physics Letters

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We bring together optical absorption spectroscopy, photoconductivity, and first principles calculations to reveal the electronic structure of the room temperature ferroelectric Ca3Ti2O7. The 3.94 eV direct gap in Ca3Ti2O7 is charge transfer in nature and noticeably higher than that in CaTiO3 (3.4 eV), a finding that we attribute to dimensional confinement in the n = 2 member of the Ruddlesden-Popper series. While Sr substitution introduces disorder and broadens the gap edge slightly, oxygen deficiency reduces the gap to 3.7 eV and gives rise to a broad tail that persists to much lower energies.

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Photoconductivity in Materials Research

Cited by 3 publications

References 25 publications

Radiation sensors based on GaN microwires

Radiation sensors based on GaN microwires

Determination of the transport parameters of nanocrystalline CdSe:Cu thin films

Optical spectroscopy and band gap analysis of hybrid improper ferroelectric Ca3Ti2O7

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