Bulk growth of uniform and near stoichiometric cadmium telluride

Swain, Santosh K.; Cui, Yunlong; Datta, Amlan; Bhaladhare, Sachin; Rao, Manchanahalli Rohan; Bürger, A.; Lynn, Kelvin G.

doi:10.1016/j.jcrysgro.2013.12.004

Cited by 14 publications

(11 citation statements)

References 11 publications

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“…CdTe single crystals were grown from melt using the vertical Bridgman technique, where the growth details are described elsewhere 21, 22 . Defects in the samples were investigated by thermoelectric-effect spectroscopy (TEES).…”

Section: Introductionmentioning

confidence: 99%

Self-compensation in arsenic doping of CdTe

Ablekim

Swain

Yin

et al. 2017

Sci Rep

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Efficient p-type doping in CdTe has remained a critical challenge for decades, limiting the performance of CdTe-based semiconductor devices. Arsenic is a promising p-type dopant; however, reproducible doping with high concentration is difficult and carrier lifetime is low. We systematically studied defect structures in As-doped CdTe using high-purity single crystal wafers to investigate the mechanisms that limit p-type doping. Two As-doped CdTe with varying acceptor density and two undoped CdTe were grown in Cd-rich and Te-rich environments. The defect structures were investigated by thermoelectric-effect spectroscopy (TEES), and first-principles calculations were used for identifying and assigning the experimentally observed defects. Measurements revealed activation of As is very low in both As-doped samples with very short lifetimes indicating strong compensation and the presence of significant carrier trapping defects. Defect studies suggest two acceptors and one donor level were introduced by As doping with activation energies at ~88 meV, ~293 meV and ~377 meV. In particular, the peak shown at ~162 K in the TEES spectra is very prominent in both As-doped samples, indicating a signature of AX-center donors. The AX-centers are believed to be responsible for most of the compensation because of their low formation energy and very prominent peak intensity in TEES spectra.

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Section: Introductionmentioning

confidence: 99%

Self-compensation in arsenic doping of CdTe

Ablekim

Swain

Yin

et al. 2017

Sci Rep

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“…It should be noted that undoped crystal growths performed in the author’s laboratory, under identical conditions of growth, stoichiometry, and cooling have resulted in inclusion free ingots as revealed by IR. 8 The CdTe phase diagram indicates that there exists a maximum solubility of ~5.1×10 18 atoms/cm 3 for Cd and ~1.6×10 19 atoms/cm 3 for Te in the CdTe lattice. 9 Any initial excess Cd or Te greater than these concentrations is expected to contribute to second phase volume.…”

Section: Results and Analysismentioning

confidence: 99%

p-type doping efficiency in CdTe: Influence of second phase formation

McCoy

Swain

Sieber

et al. 2018

Journal of Applied Physics

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Cadmium telluride (CdTe) high purity, bulk, crystal ingots doped with phosphorus were grown by the vertical Bridgman melt growth technique to understand and improve dopant solubility and activation. Large net carrier densities have been reproducibly obtained from as-grown ingots, indicating successful incorporation of dopants into the lattice. However, net carrier density values are orders of magnitude lower than the solubility of P in CdTe as reported in literature, 10/cm to 10/cm [J. H. Greenberg, J. Cryst. Growth , 1-11 (1996) and R. B. Hall and H. H. Woodbury, J. Appl. Phys.(12), 5361-5365 (1968)], despite comparable starting charge dopant densities. Growth conditions, such as melt stoichiometry and post growth cooling, are shown to have significant impacts on dopant solubility. This study demonstrates that a significant portion of the dopant becomes incorporated into second phase defects as compounds of cadmium and phosphorous, such as cadmium phosphide, which inhibits dopant incorporation into the lattice and limits maximum attainable net carrier density in bulk crystals. Here, we present an extensive study on the characteristics of these second phase defects in relation to their composition and formation kinetics while providing a pathway to minimize their formation and enhance solubility.

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“…To ensure the statistics, we randomly chose a smaller sample from another part of the ingot to investigate the distribution of Te inclusions. [20] demonstrated production of inclusion-free CdTe ingots grown by the vertical Bridgman growth technique by employing a fast growth rate. Our present result for CMT growth also agrees very well with the observation by Swain et al [20].…”

Section: Resultsmentioning

confidence: 99%

“…[20] demonstrated production of inclusion-free CdTe ingots grown by the vertical Bridgman growth technique by employing a fast growth rate. Our present result for CMT growth also agrees very well with the observation by Swain et al [20]. It is to be noted that in our study, unlike Swain et al, no excess cadmium was added to the initial charge.…”

Section: Resultsmentioning

confidence: 99%

“…These large star-like defects also severely hinder the charge-transport characteristics [19]. In the recent past, Swain et al [20] demonstrated the feasibility of growing CdTe crystals by the vertical Bridgman technique that were free from Te inclusions with a size > 1 µm. In this paper we report the growth of CMT crystals that are free from Te inclusions with a size > 1 µm using the vertical Bridgman technique.…”

Section: Introductionmentioning

confidence: 99%

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Growth of CdMnTe free of large Te inclusions using the vertical Bridgman technique

Roy

Camarda

Cui

et al. 2019

Journal of Crystal Growth

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We grew Cd 1-x Mn x Te crystals with a nominal composition of 5% Mn and 95% Cd using the vertical Bridgman technique. We were able to grow crystals from as-received starting material that were free of secondary phases, such as Te inclusions with a size > 1-µm diameter, without adding compensating Cd to the initial charge. The Te precipitations (size < 1-µm diameter) were found to segregate towards the last-to-freeze section of the ingot. Te inclusions with a size 5-7 µm were observed at the grain boundary located near the last-to-freeze section, while the bottom and middle parts of the ingot showed no Te inclusions, even at the grain boundaries. X-ray topographic analysis was used to characterize the distribution of thermal stress in the ingot.

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Bulk growth of uniform and near stoichiometric cadmium telluride

Cited by 14 publications

References 11 publications

Self-compensation in arsenic doping of CdTe

Self-compensation in arsenic doping of CdTe

p-type doping efficiency in CdTe: Influence of second phase formation

Growth of CdMnTe free of large Te inclusions using the vertical Bridgman technique

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