Detection of negative photoconductivity in CdxFe1−xSe system

Joshi, N.V.; Mogollón, Leticia; Sánchez, José G.; Martín, Juan Vicente González

doi:10.1016/0038-1098(88)90676-x

Cited by 4 publications

(1 citation statement)

References 15 publications

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“…10 The observed polarization dependence of the PC spectra is indicative of crystal field splitting. 11 Previously, positive photoresistance effect was observed in several semiconductor materials/systems such as Co-doped Si, 12 GaAs/AlGaAs, 13 p-type Cd x Fe 1Àx Se, 14 Ga-doped PbTe, 15 amorphous Se, 16 g-In 2 S 3 17 and ZnO. 18 In most cases, the explanation for this effect has been the reduction of the major carrier concentration due to impurity levels, which act as recombination centers.…”

Section: Introductionmentioning

confidence: 99%

Conducting behavior of chalcopyrite-type CuGaS₂ crystals under visible light

Cholula-Díaz

Barzola‐Quiquia

Kranert

et al. 2014

Phys. Chem. Chem. Phys.

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Millimeter size high quality crystals of CuGaS2 were grown by chemical vapor transport. The highly ordered chalcopyrite structure is confirmed by X-ray diffraction and Raman spectroscopy. According to energy dispersive X-ray spectroscopy the composition of the crystals is very close to the formula CuGaS2. Room temperature photoluminescence measurements indicate the presence of an emission peak at about 2.36 eV that can be related to a donor-acceptor pair transition. The electrical resistance as a function of temperature is very well described by the Mott variable range hopping mechanism. Room temperature complex impedance spectroscopy measurements were performed in the alternating current frequency range from 40 to 10(7) Hz in the dark and under normal light. According to the impedance spectroscopy data the experimental results can be well described by two circuits in series, corresponding to bulk and grain boundary contributions. An unusual positive photoresistance effect is observed in the frequency range between 3 and 30 kHz, which we suggest to be due to intrinsic defects present in the CuGaS2 crystal.

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Section: Introductionmentioning

confidence: 99%

Conducting behavior of chalcopyrite-type CuGaS₂ crystals under visible light

Cholula-Díaz

Barzola‐Quiquia

Kranert

et al. 2014

Phys. Chem. Chem. Phys.

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The frequency-dependent AC photoresistance behavior of ZnO thin films grown on different sapphire substrates

Cholula-Díaz

Barzola‐Quiquia

Videa

et al. 2017

Phys. Chem. Chem. Phys.

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Zinc oxide (ZnO) thin films were grown by pulsed layer deposition under an N atmosphere at low pressures on a- and r-plane sapphire substrates. Structural studies using X-ray diffraction confirmed that all films had a wurtzite phase. ZnO thin films on a- and r-plane sapphire have grown with orientations along the [0002] and [112[combining macron]0] directions, respectively. Room temperature photoluminescence measurements indicate that the presence of native point defects (interstitial zinc, oxygen vacancies, oxygen antisites and zinc vacancies) is more preponderant for ZnO thin films grown on the r-plane sapphire substrate than the sample grown on the a-plane sapphire substrate. Room temperature impedance spectroscopy measurements were performed in an alternating current frequency range from 40 to 10 Hz in the dark and under normal light. An unusual positive photoresistance effect is observed at frequencies above 100 kHz, which we suggest to be due to intrinsic defects present in the ZnO thin films. Furthermore, an analysis of the optical time response revealed that the film grown on the r-plane sapphire substrate responds faster (characteristic relaxation times for τ, τ and τ of 0.05, 0.26 and 6.00 min, respectively) than the film grown on the a-plane sapphire substrate (characteristic relaxation times for τ, τ and τ of 0.10, 0.73 and 4.02 min, respectively).

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Anomalous photoconductivity in gamma In2Se3

Sreekumar

Jayakrishnan

Kartha

et al. 2006

Journal of Applied Physics

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Negative photoconductivity in indium selenide ͑␥-In 2 Se 3 ͒ thin films was observed at room temperature and was attributed to trapping of electrons and destruction of minority carriers during illumination through recombination. Photoconductivity of the films exhibited a strong dependence on the concentration of indium in the films. Photoconductivity decreased gradually and became negative as indium concentration increased. But there was no considerable variation in the optical band gap ͑1.84 eV͒ of the films, on varying indium concentration. Increase of indium concentration introduced defect levels at 1.46 and 1.32 eV above the valance band. Photoluminescence study revealed the emission to a recombination center, which is situated at 290 meV above valance band for all the samples. Levels at 1.46 and 1.32 eV prevented photogenerated carriers from reaching conduction band, during illumination. Thus the capture of conduction band electrons and destruction of minority carries via recombination, resulted in negative photoconductivity.

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Detection of negative photoconductivity in CdxFe1−xSe system

Cited by 4 publications

References 15 publications

Conducting behavior of chalcopyrite-type CuGaS₂ crystals under visible light

Conducting behavior of chalcopyrite-type CuGaS₂ crystals under visible light

The frequency-dependent AC photoresistance behavior of ZnO thin films grown on different sapphire substrates

Anomalous photoconductivity in gamma In2Se3

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Detection of negative photoconductivity in CdxFe1−xSe system

Cited by 4 publications

References 15 publications

Conducting behavior of chalcopyrite-type CuGaS2 crystals under visible light

Conducting behavior of chalcopyrite-type CuGaS2 crystals under visible light

The frequency-dependent AC photoresistance behavior of ZnO thin films grown on different sapphire substrates

Anomalous photoconductivity in gamma In2Se3

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Product

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Conducting behavior of chalcopyrite-type CuGaS₂ crystals under visible light

Conducting behavior of chalcopyrite-type CuGaS₂ crystals under visible light