The Influence of Constitutional Supercooling on the Distribution of Te-Particles in Melt-Grown CZT

• Published in: Journal of electronic materials Vol. 44; no. 11; pp. 4604 - 4621
• Main Authors: Henager, CHARLES H., Alvine, Kyle J., Bliss, Mary, Riley, Brian J., Stave, Jean A.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.11.2015; Springer Nature B.V; Springer
• Subjects: Atoms & subatomic particles; Characterization and Evaluation of Materials; Chemistry and Materials Science; Constitutional Supercooling; Crystal Characterization; Crystallography; CZT; Electronics and Microelectronics; Instrumentation; Materials Science; Morphology; Optical and Electronic Materials; Particle Distributions; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Rayleigh Instability; Solid State Physics; Te-particles; constitutional supercooling; crystal characterization; CZT; particle distributions; Rayleigh instability; Te-particles
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-015-3995-y

A section of a vertical gradient freeze Cd 0.9 Zn 0.1 Te boule approximately 2100 mm 3 with a planar area of 300 mm 2 was prepared and examined using transmitted infrared microscopy at various magnifications to determine the three-dimensional spatial and size distributions of Te-particles over large longitudinal and radial length scales. Te-particle density distributions were determined as a function of longitudinal and radial positions in these strips and exhibited a multi-modal log-normal size density distribution that indicated a slight preference for increasing size with longitudinal growth time, while showing a pronounced cellular network structure. Higher magnification images revealed a typical Rayleigh-instability pearl string morphology with large and small satellite droplets. This study includes solidification experiments in small crucibles of 30:70 mixtures of Cd:Te performed over a wide range of cooling rates which clearly demonstrated a growth instability with Te-particle capture that is suggested to be responsible for one of the peaks in the size distribution using size discrimination visualization. The results are discussed with regard to a manifold Te-particle genesis history as Te-particle direct capture from melt–solid growth instabilities due to constitutional supercooling and as Te-particle formation from the breakup of Te-ribbons via a Rayleigh–Plateau instability.