Imperfection photoconductivity peak related to the Urbach's absorption edge in Cd1−xMnxTe and CdTe

Szadkowski, A.; Lubomirska-Wittlin, A.

doi:10.1016/0038-1098(86)90232-2

Cited by 3 publications

(1 citation statement)

References 11 publications

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“…The shape of the PC peak indicates that even for hv 2 E, the intrinsic PC is smaller than the extrinsic PC caused by the photoionization of iron. (The mechanism of formation of an imperfection PC peak due to competition between the extrinsic and intrinsic PC has been described by Szadkowski and Lubomirska-Wittlin (1986).) For the left-hand side of the PC peak in figure 1 the Pccomponents other than that connected with iron can be neglected.…”

Section: Optical Ionization Energymentioning

confidence: 99%

The Fe^2+/3+donor level in CdTe

Szadkowski

1990

J. Phys.: Condens. Matter

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Photoconductivity, absorption and temperature dependence of conductivity were studied in CdTe:Fe crystals. The position of the Fe2+/3+ donor level has been determined. It lies 130-150 meV above the top of the valence band. The value of the optical ionization energy has been confirmed as 1455 meV. The lattice relaxation energy has been found to be below 20 meV. The Auger photoconductivity originated by the 5E to 5T2 intracentre transitions within the Fe2+ centres has been observed.

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Section: Optical Ionization Energymentioning

confidence: 99%

The Fe^2+/3+donor level in CdTe

Szadkowski

1990

J. Phys.: Condens. Matter

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Transient photoconductivity in CdMnTe semimagnetic semiconductor

El-Darazi¹,

Calas²,

Lascaray³

et al. 1991

Physica Status Solidi (b)

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In the past few years a lot of work has been done on the spectral photoconductivity versus temperature and composition in the semimagnetic semiconductor CdMnxTe /1 to 8 / . In the case of high Mn concentration ( x > 0.5) Lascaray et al. / 6 / have explained the spectral photoconductivity b y taking into account the intra Mn transition 6A1 + (4T1, 4T2). When these transitions appear, because of the competition with the intrinsic absorption, the number of electrons excited in the conduction band decreases and the photocurrent decreases as well. This explains the appearance of a peak in the PC spectra for energies lower than the intra Mn transition. For lower x, the gap decreases and the energy of (6A1, 4T1) is higher than the gap energy. These authors have observed a drastic effect of the frequency and applied electric field on the shape of PC spectra. They have interpreted these results in the framework of a two-level system involving a recombination level Es and a sensitizing trap center E,, as introduced b y Bube / 9 / to explain the important PC of 11-VI compounds.In this work by using transient photoconductivity we show that there exist two rather different lifetimes ( b y an order of magnitude), which could support the existence of two different levels in the gap with different roles. 1-xThe growth technique and the structural characterisations of these samples have been already described / l o / . The ohmic contacts were obtained by a gold chemical deposition at 250 O C in hydrogen vapor during 3 min.A pulse of monochromatic light is sent at room temperature on the sample. The pulse is given by a dye laser. The width of the pulse is 10 ns. The wavelength can be adjusted between 360 and 740 nm.When the laser beam is stopped, the photoconductivity decreases and we study this decreasing with time. Several compositions were studied, namely x = 0 . 7 2 , x = 0.52, x = 0 . 3 0 , and x = 0.115.A iypical experimental curve is given on Fig. 1. One can see the same behaviour for other compositions.In order to get quantitative results, the P S ( t ) curves were analysed following the expression I = Z A. exp(-t/T.). The time constant T . was determined for each ) Place Euggne

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Optical studies of Cd1−xMnxTe films grown on (001)InSb by pulsed laser evaporation and epitaxy

Labrie

Qiu

Wang

et al. 1992

Journal of Applied Physics

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Photoluminescence, photoreflectance, and photovoltaic measurements have been used to characterize Cd1−xMnxTe (CMT) epilayers, 0.5–1.4 μm thick, grown on (001) InSb by pulsed laser evaporation and epitaxy. The measurements indicate high-quality epilayers comparable to the best bulk CMT or of CMT grown by molecular beam epitaxy. In some cases, a small gradient of Mn composition along the epilayer thickness is indicated by the photoreflectance data.

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Imperfection photoconductivity peak related to the Urbach's absorption edge in Cd1−xMnxTe and CdTe

Cited by 3 publications

References 11 publications

The Fe^2+/3+donor level in CdTe

The Fe^2+/3+donor level in CdTe

Transient photoconductivity in CdMnTe semimagnetic semiconductor

Optical studies of Cd1−xMnxTe films grown on (001)InSb by pulsed laser evaporation and epitaxy

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Imperfection photoconductivity peak related to the Urbach's absorption edge in Cd1−xMnxTe and CdTe

Cited by 3 publications

References 11 publications

The Fe2+/3+donor level in CdTe

The Fe2+/3+donor level in CdTe

Transient photoconductivity in CdMnTe semimagnetic semiconductor

Optical studies of Cd1−xMnxTe films grown on (001)InSb by pulsed laser evaporation and epitaxy

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Product

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The Fe^2+/3+donor level in CdTe

The Fe^2+/3+donor level in CdTe