Effect of the Growth Rate on the Optical and Terahertz Characteristics of Temperature Gradient Solvent Method‐Grown ZnTe Single Crystals

A ZnTe crystal is a highly promising electro‐optical single crystal for terahertz (THz) generation and detection. However, achieving large‐sized, high‐quality ZnTe crystals for such applications still remains a major challenge owing to incorporation of the tellurium (Te) secondary phase and defect generation during crystal growth, affecting the THz characteristics of ZnTe. Hence, precise growth control along with a comprehensive assessment of optical quality is imperative to develop ZnTe crystals for such advanced applications. This article presents a detailed assessment of optical and THz characteristics of ZnTe crystals grown by the temperature gradient solvent method at two different growth rates of 1 mm hr−1 and 0.4 mm hr−1. The assessment of Te precipitates in grown ZnTe crystals shows a drastic reduction in Te precipitates in ZnTe crystals grown at 0.4 mm hr−1. This is ascertained by a detailed optical assessment through spectroscopic studies using Fourier transform infrared spectroscopy, showing a high infrared transmittance of ≈60%, Raman spectra, showing high optical and crystalline quality, and photoluminescence, showing lower defect luminescence. This has culminated in the enhancement of THz generation and detection characteristics of ZnTe crystals, underlining the potential of this study in enrooting the issues in ZnTe crystal growth for high‐end THz applications.