Investigations on Optical Scatter Particles during CdSiP$lt;inf$gt;2$lt;/inf$gt; Crystals Growth

Polycrystalline charges of CdSiP2 (CSP) were synthesized by direct reaction method using P, Si, and Cd elements as the initial materials. Single crystals with the dimension of 8 mm in diameter and 40 mm in length were successfully grown by vertical Bridgman method. The dimension and the composition of the optical scatter particles in the CSP crystals were identified by SEM measurement. The results show that most of optical scattering particles are round-shaped with dimension of 2-8 μm. The EDS measurement result shows that the atomic percent of Si in the op- tical scattering particles is over 88%. The synthesis mechanism of CSP by single temperature zone method was studied by powder XRD. The results show that there is some unreacted silicon left when synthsized process is carried out be- low 1150℃. By optimizing the synthesis parameters and the Si inclusions were successfully restrained and the high optical quality CSP single crystal was obtained.