Effect of Acid Impurities on Nucleation and Growth Mechanism of Cadmium Selenide Single Crystal in Silica Hydrogels

Abstract

Single crystal of Cadmium selenide has been grown in silica hydro gel at ambient temperature by reacting aqueous solutions of Cd EDTA and H₂NCSeNH₂. Foreign impurities such as H₂SO₄ ,HCl, HNO₃, CH₃COOH, HClO₄ acids in small quantities added with a view to modify the initial characteristics of the growth medium helped to suppress the Nucleation density and improve the size and optical transparency of the crystals. The crystals grown, in silica gels with HClO₄ and HNO₃ impurities were quite flawless with well defined edges and faces, and up to a maximum size of about four times larger than the ones obtained without impurities. With the impurity the number of lies rings reduces and more transparent single crystals were observed.