Etch Pits and Polarity in CdTe Crystals

Cd 1-x Mn x Te (x=0.2, CdMnTe) crystal was grown by the vertical Bridgman method, which exhibits a pure zincblende structure in the whole ingot. The major defect, twins, which is fatal to CdMnTe crystal, was analyzed with scanning electron microscopy (SEM), X-ray energy disperse spectroscopy (XEDS) and optic microscopy on the chemical etching surface. The twins observed in the as-grown ingot are mainly lamellar ones, which lie on the {111} faces from the first-to-freeze region of the ingot and run parallel to the growth axis of the ingot. Coherent twins with {115} t -{111} h orientations when indexed with respect to both the twin and host orientations, are often found to be terminated by {110} t -{114} h lateral twins. Te inclusions with about 20 µm in width are observed to preferentially decorate the lamellar twin boundaries. The origin of the twins, relating to the growth twin and the phase transformation twin, is also discussed in this paper.

Section: Methodsmentioning

confidence: 99%

Twins in CdMnTe single crystals grown by Bridgman method

Zhang¹,

Wang

et al. 2009

“…Selected samples were then characterized determining the etch pit density after immersion in the Inoue E-Ag1 solution [14], using optical microscopy. Crystal quality was studied performing rocking curves with a D5000 HR diffractometer (Huber), selecting the CdTe (2 2 0) reflection.…”

Section: Methodsmentioning

confidence: 99%

Addition of an insulating element to the Modified Markov Method for CdTe single crystals growth

Saucedo

Ruiz

Fornaro

et al. 2004

CdTe single crystal, were grown by the Modified Markov Method. We have introduced an insulating element between the furnace and the growth chamber, trying to minimize the radiation effects in the crystal. Numerical simulation of the heat transfer phenomena predict a reduction of the axial temperature gradient in the growth chamber, confirming by numerical experimental measurements, leading to a more uniform growth. An improvement in the surface morphology and in the crystal quality as well was achieved, evaluated by the combination of X-ray rocking curves, etch pit density determination and low temperature photoluminescence.

“…The most used etching for CdTe are Inoue [6] and Nakagawa [7] solutions in addition to FeCl 3 [8], bromine-methanol [9] and B-solution [10]. The Inoue or E-Ag1 (20 ml of E-solution HNO 3 :H 2 O:K 2 Cr 2 O 7 5 ml:10 ml:2 g with 1 mg of AgNO 3 ) and Nakagawa solutions (HF:H 2 O 2 :H 2 O 3:2:2) are usually employed for revealing distribution and density of dislocations on the Te (111) surface.…”

Section: Introductionmentioning

confidence: 99%

Revealing of defects in CdTe crystals by DSL etching

Bissoli

Weyher

Zappettini³

et al. 2005

The effect of DS(L) (Diluited Sirtl with or without Light) solution on CadmiumTelluride crystals has been studied in comparison with the actions due to Inoue and Nakagawa etching solutions. The use of chemical etching to reveal extended defects is a fast and useful technique for characterizing the crystals with the aim of improving the growth technology and better devices performance. In fact it is well known that extensive defects in CdTe crystals have a relevant role on the material properties and finally on the devices performance. DSL solution previously used on Si, GaAs and InP, here has been used for the first time on CdTe crystals. The etching solutions have been used to characterize crystals with two different characteristics: the first group shows high electrical resistivity and close to stoichiometry composition, the second one shows low resistivity behaviour and large Te deviation. We report here the preliminary results of the characterization of these crystals with the DSL etching.