Cathodoluminescence characterization of Ge-doped CdTe crystals

Pal, U.; Fernández, Paloma; Piqueras, J.; Sochinskii, N.V.; Diéguez, E.

doi:10.1063/1.360173

Cited by 37 publications

(22 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3͑a͒. As previously re- ported for Ge-doped CdTe, 8 two bands centered at about 810 and 900 meV are observed while the near band-edge emission is not detected. The spectra acquired by scanning the beam on a sub-boundary and on the background are qualitatively similar to some increase of the CL intensity on the sub-boundary.…”

supporting

confidence: 56%

“…8,15,16 The bright CL contrast of sub-boundaries and other defects in the unmodified part of the substrate indicates that extended structural defects are effective gettering sites for the Ge-related point defect complexes. Near the interface the relative contribution of the Ge-related defects to the luminescence decreases.…”

mentioning

confidence: 99%

“…[7][8][9] However, very limited attention has been given to the study of luminescence properties of high-resistivity doped CdTe and epitaxial structures made from it. In the particular case of CdTe:Ge, which is the substrate used in this work, previous CL studies 8 show an enhancement of 810 and 910 meV emissions as a result of Ge doping. Both bands show an increase in intensity after an annealing of the Ge-doped sample which is attributed to the formation of a complex center involving Ge on Cd sites.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Effect of α-HgI2 epitaxial growth on the defect structure of CdTe:Ge substrates

Panin

Piqueras

Sochinskii

et al. 1997

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

The ␣-HgI 2 /CdTe:Ge heterostructures have been studied by cathodoluminescence ͑CL͒ in the scanning electron microscope. The ␣-HgI 2 expitaxial growth was shown to cause an enhancement of the CL intensity in a layer of the substrate extending up to about 500 m from the ␣-HgI 2 /CdTe:Ge interface. CL spectra of the layer reveal the appearance of a band related to tellurium vacancies as well as the decrease of the emission attributed to defect complexes involving Ge. The data obtained indicate that Ge-impurity gettering and V Te generation at the interface take place during ␣-HgI 2 epitaxial growth.

show abstract

supporting

confidence: 56%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Effect of α-HgI2 epitaxial growth on the defect structure of CdTe:Ge substrates

Panin

Piqueras

Sochinskii

et al. 1997

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

show abstract

“…These luminescence bands peaked at about 1.4, 0.93, 0.82, 0.77, and 0.66 eV, have been previously studied in CdTe bulk crystals and attributed to different defect centers. 12,[15][16][17][18] The highest relative intensity corresponds to the bands peaked at 1.4 and 0.66 eV. After laser recrystallization, a bright region surrounding the irradiation spots are observed in the CL images.…”

Section: ͓S0003-6951͑97͒01947-5͔mentioning

confidence: 94%

“…Cathodoluminescence ͑CL͒ microscopy has been shown to be a very useful tool to characterize CdTe bulk crystals submitted to different technological treatments like thermal annealing, 9-11 doping, 12 or epitaxial overgrowth. 13 The capability to obtain both spectral and spatial resolution allows us to gain quite valuable information about the defect structure of the material.…”

Section: ͓S0003-6951͑97͒01947-5͔mentioning

confidence: 99%

Cathodoluminescence study of laser recrystallized CdTe layers

Fernández

Piqueras

Sochinskii

et al. 1997

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

CdTe͑100͒/GaAs͑100͒ and CdTe͑111͒/CdTe͑111͒ layers grown by metalorganic vapor phase epitaxy ͑MOVPE͒ were investigated. The layers were recrystallized to improve their morphology by scanning the surface with a 100 m diameter spot from an Ar ion laser beam ( ϭ514.4 nm). Cathodoluminescence spectra from both as-grown and recrystallized CdTe MOVPE layers are used to monitor the effect of the recrystallization procedure. The laser recrystallization results in important changes on the spectral distribution of luminescence. Deep-level bands associated to different defects are shown to be very sensitive to the laser recrystallization procedure. The effect of the different substrates on the defect structure of the layers is also related to the changes observed in the cathodoluminescence spectra. © 1997 American Institute of Physics. ͓S0003-6951͑97͒01947-5͔Metalorganic vapor phase epitaxy ͑MOVPE͒ is a technique commonly used to grow CdTe layers on different lattice mismatched substrates like Si, GaAs, sapphire, etc. 1 These layers are used as substrates for subsequent epitaxial growth of Hg 1Ϫx Cd x Te layers for infrared applications ͑for recent examples, see Refs. 2-5͒. It is widely accepted that the properties of CdTe MOVPE layers are strongly dependent on several technological factors, among which the substrate nature is one of the most important. 6 In particular, previous studies of CdTe/sapphire and CdTe/GaAs layers grown by a low-temperature MOVPE have shown that the as-grown layers have a low quality, rough surface due to strain raised from the large lattice mismatch. [6][7][8] To overcome this problem, postgrowth laser recrystallization has been recently proposed as a method to improve the surface morphology of CdTe MOVPE layers. 8 Nevertheless, it is still an open question how the laser recrystallization procedure affects other properties of the layers besides surface morphology.Cathodoluminescence ͑CL͒ microscopy has been shown to be a very useful tool to characterize CdTe bulk crystals submitted to different technological treatments like thermal annealing, 9-11 doping, 12 or epitaxial overgrowth. 13 The capability to obtain both spectral and spatial resolution allows us to gain quite valuable information about the defect structure of the material. Though bulk crystals have been extensively studied by luminescence techniques, not so much work has been done to characterize CdTe epitaxial layers. In this letter, we report the results on cathodoluminescence studies of asgrown and laser recrystallized CdTe/GaAs and CdTe/CdTe MOVPE layers and show the effect of the laser recrystallization on the radiative defects contributing to the CL emission of the layers. The influence of the substrate on the behavior of the epilayers under laser irradiation is also reported.The samples investigated were CdTe͑100͒ and CdTe͑111͒ layers grown on GaAs͑100͒ and CdTe͑111͒ substrates by MOVPE. The layer thicknesses were in the range 4-10 m. The MOVPE growth was carried out at 340°C for 3-5 h using dimethylcadmium and diisopropiyl tel...

show abstract

Energetics and Electronic Properties of Interstitial Chlorine in CdTe

Orellana

Menéndez-Proupín

Flores

2018

Physica Status Solidi (b)

View full text Add to dashboard Cite

The role of interstitial chlorine in the electronic properties of CdTe is addressed by density functional theory calculations including hybrid functionals and large unit cells. The stability and diffusion energy barriers of the impurity are analyzed as a function of the Fermi level position in the band gap. Chlorine is found to be stable in at least five interstitial sites with rather close formation energies, suggesting that they are all probable to be found. In p‐type CdTe, the most stable sites are at the center of a CdTe bond and at a split‐interstitial configuration, both acting as shallow donors. Whereas in n‐type CdTe, it is found at the tetrahedral site surrounded by Cd hosts, acting as a shallow acceptor. We also find that chlorine can induce a deep acceptor level in the bandgap after binding with three Cd host atoms, which can explain the experimentally observed high resistivity in Cl‐doped CdTe. The energy barriers for chlorine diffusion in both p‐type and n‐type CdTe are also discussed.

show abstract

Cathodoluminescence characterization of Ge-doped CdTe crystals

Cited by 37 publications

References 13 publications

Effect of α-HgI2 epitaxial growth on the defect structure of CdTe:Ge substrates

Effect of α-HgI2 epitaxial growth on the defect structure of CdTe:Ge substrates

Cathodoluminescence study of laser recrystallized CdTe layers

Energetics and Electronic Properties of Interstitial Chlorine in CdTe

Contact Info

Product

Resources

About