铋掺杂砷化镓晶体的坩埚下降法生长研究

Growth and Characterization of Bi-doped GaAs Crystal by Bridgman Method

使用<511>取向Ga As籽晶,在直径2英寸的p BN坩埚中生长了2.5%Bi掺杂的Ga As晶体。能量分散谱仪(EDS)和透过光谱均有Bi相关谱峰的存在,说明Bi原子已掺杂到Ga As晶体中。X射线双摇摆曲线测得半高峰宽值为42″。与未掺杂Ga As晶体相比,所得晶体的禁带宽度出现红移,从1.43 e V移至近1.39 e V。扫面式电子显微镜(SEM)显示晶体中存在少量富Bi包裹物,晶体质量有待进一步改进。

Using 511 oriented Ga As seed and p BN crucible,2-inch Ga As1- xBixcrystal with a nominal composition of x = 0. 025 was obtained. Bi-related peaks were observed in energy dispersive spectroscopy（ EDS） spectra and transmittance spectra,which means that Bi has entered into Ga As lattices. The double-crystal X-ray rocking curve was measured and the FWHM value is about 42 arcsec.Compared with undoped Ga As crystal,the band gap of as-grown crystal shifts to red wave from 1. 43 e V to 1. 39 e V. Bi-rich inclusions were observed by