Electrical and optical properties of lodine doped CdZnTe layers grown by metalorganic vapor phase epitaxy

Yasuda, K.; Kojima, Kiyoshi; Mori, Koichi; Kubota, Yoichi; Nimura, T.; Inukai, F.; Asai, Y.

doi:10.1007/s11664-998-0009-3

Cited by 8 publications

(5 citation statements)

References 13 publications

(19 reference statements)

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“…20,21 The peaks at 1.5733 and 1.5653 eV are identified as the first longitudinal-optical (LO) phonon replica of the FE and (A 0 , X) transitions, respectively. 19 The broad emission at around 1.47 eV is due to the deep donor-acceptor pair (DAP) transition.…”

Section: Resultsmentioning

confidence: 99%

Direct growth of high-quality thick CdTe epilayers on Si (211) substrates by metalorganic vapor phase epitaxy for nuclear radiation detection and imaging

Niraula

Yasuda

Ohnishi

et al. 2006

Journal of Elec Materi

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Direct growth of high-quality, thick CdTe (211) epilayers, with thickness up to 100 mm, on Si (211) substrates in a vertical metalorganic vapor phase epitaxy system is reported. In order to obtain homo-orientation growth on Si substrates, pretreatment of the substrates was carried out in a separate chamber by annealing them together with pieces of GaAs at 800-900°C in a hydrogen environment. Grown epilayers had very good substrate adhesion. The full-width at half-maximum (FWHM) value of the x-ray double-crystal rocking curve from the CdTe (422) reflection decreased rapidly with increasing layer thickness and remained between 140-200 arcsec for layers .18 mm. Photoluminescence measurement at 4.2 K showed high-intensity, bound excitonic emission and very small defect-related deep emissions, indicating the high crystalline quality of the grown layers. Furthermore, a CdTe/n 1 -Si heterojunction diode was fabricated that exhibited clear rectifying behavior.

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Section: Resultsmentioning

confidence: 99%

Direct growth of high-quality thick CdTe epilayers on Si (211) substrates by metalorganic vapor phase epitaxy for nuclear radiation detection and imaging

Niraula

Yasuda

Ohnishi

et al. 2006

Journal of Elec Materi

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“…These peaks are attributed to light hole-free exciton (LH) and heavy hole-free exciton (HH), respectively, based on the data obtained for CdTe layers grown on GaAs/Si substrates, which was confirmed by the reflectance measurement. The LH emission appears at a lower energy than that of HH emission as CdTe layers on Si substrates experience a tensile stress (as discussed below) like CdTe on GaAs/Si substrates or ZnTe on GaAs substrates [12,16]. The peaks at 1.5733 and 1.5653 eV are identified as the first longitudinal-optical (LO) phonon replica of the FE and (A1,X) transitions, respectively [14].…”

Section: Resultsmentioning

confidence: 99%

Direct growth of high-quality CdTe epilayers on Si(211) substrates by metalorganic vapor-phase epitaxy

Niraula

Yasuda

Ohnishi

et al. 2005

Journal of Crystal Growth

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“…Figure 2 shows a PL spectrum of the layer which was lightly doped with iodine (n $ 10 15 cm --3 ), carried out at 20 K. The PL spectrum shows a sharp edge emission peak and a very broad and high intensity peak at lower energy region. The sharp peak at 7814 A (1.5863 eV) is attributed to a neutral donor bound exciton line (D 0 , X) with iodine as donor, and the week broad shoulder at 7889 A (1.5712 eV) as due to the acceptor bound exciton (A 0 , X) line [7]. The broad and most intense peak at 8688 A (1.4267 eV), whose intensity increases with the doping level, is due to the donor-acceptor pair recombination involving the shallow iodine donor I Te and the V Cd -I Te acceptor [8].…”

Section: Resultsmentioning

confidence: 99%

Low-Temperature Growth and Doping of CdTe Epilayers on CdTe Substrates in a Remote-Plasma-Assisted MOCVD System for Nuclear Radiation Detector Applications

Niraula

Nakamura

Aoki

et al. 2002

phys. stat. sol. (b)

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Homoepitaxial growth and n-type impurity doping of CdTe layers at low substrate temperatures were carried out for their applications in nuclear radiation detector fabrication. The grown epilayers were characterized by scanning electron microscopy, photoluminescence and Hall measurements. Highly conductive iodine doped layers could be obtained at a substrate temperature of 150 C, and these layers were found to be more suitable for radiation detector applications than other layers grown at higher substrate temperatures. The surface morphology of these homoepilayers was not very smooth, however, distinct edge emission and deep level emission bands were observed on the PL spectra at 20 K. A diode-type radiation detector fabricated using this low temperature growth and doping technique, exhibited very good rectification property with a very low value of reverse bias leakage current and an excellent nuclear radiation detection property.Introduction CdTe is a technologically important semiconductor with its applications in nuclear radiation detectors, infrared detectors, solar cells, and other optoelectronic devices, and has long been investigated [1,2]. Many device applications require low temperature growth and efficient substitutional doping with donor and/or acceptor. Particularly in the nuclear radiation detector fabrication, low device leakage current is an essential factor because it allows one to apply high electric field on the detector which, in turn, improves the charge transport properties and hence the detector performance. However, the maximum resistivity of the detector grade crystal available today is in the order of 10 9 Wcm and it suffers from excessive leakage current when a high electric field is applied on the detector. Fabricating a rectifying junction on the crystal wafer by growing an epitaxial layer on the crystal helps to suppress the leakage current significantly. However, the lack of a low temperature growth and doping technique has limited this approach because there is a possibility of initial crystal degradation at high temperature growth as the CdTe crystals are vulnerable to high temperature processing [3].We have used a remote-plasma-assisted MOCVD system for the epitaxial growth and doping of CdTe at low substrate temperature. This system has been assisted with atomic-hydrogen radicals produced in a remote plasma zone. These plasma radicals help to enhance the decomposition of source monomers and result an epitaxial growth even at low substrate temperatures. Properties of the grown epilayers doped with iodine for ntype impurity will be presented. Furthermore, performance of a diode-type nuclear ra-

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Electrical and optical properties of lodine doped CdZnTe layers grown by metalorganic vapor phase epitaxy

Cited by 8 publications

References 13 publications

Direct growth of high-quality thick CdTe epilayers on Si (211) substrates by metalorganic vapor phase epitaxy for nuclear radiation detection and imaging

Direct growth of high-quality thick CdTe epilayers on Si (211) substrates by metalorganic vapor phase epitaxy for nuclear radiation detection and imaging

Direct growth of high-quality CdTe epilayers on Si(211) substrates by metalorganic vapor-phase epitaxy

Low-Temperature Growth and Doping of CdTe Epilayers on CdTe Substrates in a Remote-Plasma-Assisted MOCVD System for Nuclear Radiation Detector Applications

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