Morphology evolution of micron-scale secondary phases in CdZnTe crystals grown by vertical Bridgman method

Secondary Phase Particles in Cesium Lead Bromide Perovskite Crystals: An Insight into the Formation of Matrix-Controlled Inclusion

“…In addition, the PbBr 2 -rich droplets were easily trapped by the S–L interface to form the SP particles due to morphological instability during the growth. This phenomenon is commonly reported in III-Vs ,, and II-VIs. − , In terms of CsPbBr 3 crystals grown from melt, three capture paths were proposed, as illustrated in Figure b–d. (I) The S–L interface changes from planar to cellular in local area due to significant constitutional supercooling, thus the off-stoichiometric droplets are retained in the matrix, Figure b.…”

“…In fact, the presence of SP particles is one of the common bulk defects in the classical compound semiconductor crystals, which markedly affects the optical and electronic device properties . Both the solid-state precipitated imperfections and the crystallized liquid droplets known as inclusions are observed not only in melt-grown bulk crystals, − but also in thin films. , In terms of the melt growth, the “limited growth” mechanisms of the polyhedral inclusion have been proposed. − However, the composition, morphology and size distribution of these potential SP particles in bulk CsPbBr 3 SCs are not clear, although Dmitry et al reported the light scattering and high turbidity associated defects. So far, the presence and influence of SP particles in CsPbBr 3 have been rarely investigated.…”

“…Generally, the CsPbBr 3 grows on the periphery, while CsPb 2 Br 5 grows in the remaining cavity, forming the so-called SP particles. The facet morphology of CsPb 2 Br 5 particles is confined by the anisotropic growth of the CsPbBr 3 matrix, which is called the “matrix-controlled” growth . Furthermore, CsPbBr 3 belongs to the isometric system at temperatures over 406 K; thus the polyhedral “negative crystal” within matrix also exhibits an equiaxed morphology.…”

“…This phenomenon is commonly reported in III-Vs 24,26,27 and II-VIs. [28][29][30]36 In terms of CsPbBr 3 crystals grown from melt, three capture paths were proposed, as illustrated in Figure 2b−d. (I) The S−L interface changes from planar to cellular in local area due to significant constitutional supercooling, thus the off-stoichiometric droplets are retained in the matrix, 37 and the concentration changes until it reaches the eutectic point. Then both CsPb 2 Br 5 and CsPbBr 3 crystallize simultaneously.…”

Temperature-gradient annealing of CdZnTe under Te overpressure

“…Chemical etching with a Saucedo solution at the white spot areas shown in Fig. 6(c) reveals star-shaped defects [16,17]. A possible explanation of such defect is that the exothermic reaction of elemental Te within inclusions with diffused Cd atoms generate heat and pressure on the CZT matrix inducing distortions around those Te inclusions following {110} planes.…”