Growth of Single-Crystal Cd0.9Zn0.1Te Ingots Using Pressure Controlled Bridgman Method

Abstract

We report growth of single-crystal Cd0.9Zn0.1Te ingots while using the pressure-controlled Bridgman method. The Cd pressure was controlled during growth to suppress its evaporation from the melt and reduce the size of Te inclusions in the as-grown crystals. The accelerated crucible rotation technique (ACRT) was used to suppress constitutional supercooling. The fast accelerating and slow decelerating rotation speeds were optimized. Two-inch Cd0.9Zn0.1Te single-crystal ingots without grain boundaries or twins were grown reproducibly. Glow discharge mass spectrometry results indicate the effective segregation coefficients of Zn and In dopants are 1.24 and 0.18, respectively. The full width half maximum (FWHM) of X-ray rocking curve was approximately 22.5 ″, and the IR transmittance was approximately 61%, indicating high crystallinity. The mean size of the Te inclusions was approximately 13.4 μm. Single-crystal wafers were cut into 5 × 5 × 2 mm3 slices and then used to fabricate gamma ray detectors. The energy resolution and peak-to-valley ratio maps were constructed while using 59.5 keV gamma ray measurements, which proved the high uniformity of detection performance.

Crystalline Quality, Composition Homogeneity, Tellurium Precipitates/Inclusions Concentration, Optical Transmission, and Energy Band Gap of Bridgman Grown Single-Crystalline Cd1−xZnxTe (0 ≤ x ≤ 0.1)

“…Those ingots, with a slightly convex or concave interface, showed IR transmittance lower than 60%, attributed for the authors to Te precipitates. Moreover, our IR measurements are higher than the 61% obtained by F. Yang et al [ 26 ] in Cd 0.9 Zn 0.1 Te ingots with 10 ppm (at.) Indium dopant grown by the pressure-controlled Bridgman’s method.…”

“…The optical transmission measurements were performed using a Fourier transformed infrared (IR) spectrometer (FTIRS) Perkin Elmer System 2000 model (Richmond, CA, USA), in the spectral range of 2 to 27 microns. Transmittance gives an idea of the amount of defects, since the better the crystallographic quality, the higher the transmittance [ 26 ].…”

High‐Performance X‐Ray Detector Based on Liquid Diffused Separation Induced Cs3Bi2I9 Single Crystal

“…In addition, the high fabrication and integration costs of CZT SCs still need to be overcome. [ 16 ]…”

Research on the Technological Progress of CZT Array Detectors

“…Wanqi et al [26][27][28] initiated studies on CdTe/CZT crystals using the Bridgman method as early as 1993. In 2010, Wang Tao and Jie Wanqi, among others, utilized an improved Vertical Bridgman method to fabricate CZT crystals.…”