Crystal Defect Investigation in PVT-Grown ZnSe under Different Seeding Conditions and Growth Configurations Using Synchrotron X-Ray Topography

Zinc selenide (ZnSe) is a widely utilized II-VI semiconducting material for fabricating high-performance optoelectronics devices owing to its unique electrical and optical properties. As those properties highly depend on the native point defects and impurity distribution, achieving routine production of high-quality ZnSe crystal is essential. This study conducted synchrotron white beam X-ray topography (SWBXT), optical microscopy and high-resolution triple X-ray diffraction (HRTXD) characterization on five as-grown ZnSe boules grown in physical vapor transport (PVT) method with different seeding conditions and growth configurations. Study indicated that nucleation of multiple grains is induced during seeded growth, while self-seeded boules tend to obtain single crystals. ZnSe boules grown in vertical configuration are found to have relatively poor crystalline quality comparing to horizontally grown boules that are characterized by low energy facets. The twinning mechanism is also discussed. This study successfully investigated factors that induce crystal quality variation during the growth process.