Optically detected magnetic resonance experiments on native defects in ZnGeP2

Growth and thermal annealing effect on infrared transmittance of ZnGeP2 single crystal

“…When annealing in P atmosphere, P atom diffused into the crystal, and compensated the deficiency of P in the crystals; so the transmittance increased. Combined with elucidations of the dashed line discussed above, the deficiency of P affected the transmittance not only in the range of 0.65-2.5 mm, which is in good agreement with the previously published ODMR measurements [21], but also in the range beyond 2.5 mm.…”

“…Despite other measurements such as photoluminescence (PL) [18], Rietveld refinement of XRD patterns [19,20] and magnetic circular dichroism of the absorption (MCDA) [21] were also used to identify the type of defects existed in as-grown ZnGeP 2 crystals as well as their contributions to the broad absorption band, limited works on the effect of different thermal anneal conditions, which may change the concentrations of different types of point defects have been done. In this paper, a crack-free ZnGeP 2 single crystal of diameter^8 and 40 mm length was grown using accelerated crucible rotation technique (ACRT) Bridgman method, and the effect of thermal annealing in different atmospheres on the infrared absorption was studied using vis-NIR transmission spectrum and IR transmission spectrum.…”

Growth improvement and quality evaluation of ZnGeP2 single crystals using vertical Bridgman method

“…However, crystal defects, such as micro-crack induced by anisotropic thermal expansion [6], growth striations induced by temperature oscillation [7,8], and point defects that lead to the deviation of stoichiometry always found in the as-grown ZnGeP 2 single crystals [3][4][5]. Until now, there are many theoretical [9,10] and experiments reports [11][12][13][14] on identifying the types of defects existed in as-grown ZnGeP 2 crystals and their contributions to the broad absorption band, as well as growth and post-treatment studies [15][16][17] on reducing the optical absorptions in the region of 1-2 mm. However, the complicated process in synthesis, growth, and post annealing of the ZnGeP 2 crystal makes only limited groups can prepare the high quality ZnGeP 2 crystal for high-power output uses.…”

Influence of annealing on optical and electrical properties of ZnGeP2 single crystals

“…However, stable growth of the perfect ZGP crystal with high optical quality is very difficult due to the physical and chemical properties of this material. Firstly, ZGP is a complex ternary system, and contains two volatile components, Zn and P, with high vapor pressure at the melting temperature of 1027 1C, which can result in component deviations from stoichiometry not only in the process of polycrystalline synthesis but also in the growth process of ZGP single crystal; deviations from stoichiometry can lead to the formation of large magnitude of point defects, such as zinc vacancy (V Zn ), phosphorus vacancy (V P ) and Ge-Zn substitutional defect (Ge Zn ), which mainly result in high optical absorption in the range of 0.65-2.5 mm as mentioned in some literatures [1,3,[7][8][9][10][11][12]. Secondly, the vapor pressure of phosphorus is very high above its melting point.…”

“…Some previous research suggested that the optical absorption in the range of 0.65-2.5 mm is mainly caused by the clusters of zinc vacancy [10,11]. Some other assumed that the other types of point defects besides zinc vacancy [7,12] affect the optical absorption.…”