LAUSR

Abstract Using FLUENT software to simulate the gas flow pattern of CVDZnSe under different nozzle structures including annular single nozzle, four-hole single nozzle and porous multi nozzles, it was found that the gas flow pattern distribution of the annular single-nozzle is up sparse and down dense, and a significant back-flow phenomenon occurs at the gas inlet, whereas the gas flow pattern of the four-hole single-nozzle has better uniformity and the pattern of the porous multi-nozzle is up dense and down sparse. Moreover, neither single-nozzle with four holes nor porous multi-nozzle shows back-flow phenomenon at the inlet. The characteristics of ZnSe prepared by chemical vapor deposition(CVD)method under different nozzle structures are analyzed by EDS, indicating that the stoichiometric ratio of CVDZnSe prepared by using a four-hole single-nozzle is close to “1″, with Zn/Se ratio of B-1# standing at 0.94 and the ratio of B-2# 0.93. In addition, the optical transmittance test of 6 samples shows that the Zn/Se ratio near “1″ is more conducive to improving the optical transmission for 8–14 μm. As a result, the four-hole single nozzle is more conducive to improving the uniformity of the gas flow pattern distribution and preparing CVDZnSe in a stoichiometric ratio.