用正电子研究Ⅲ-Ⅴ族化合物半导体的缺陷谱

Positon Annihilation Study of Defects in Ⅲ- Ⅴ Compound Semiconductors

简要介绍了本科研组近年来用正电子湮没谱学研究Ⅲ－Ⅴ族化合物半导体缺陷的最新进展，包括原生样品中缺陷的种类、大小、电荷态、负离子缺陷、缺陷与杂质的相互作用、辐照以及形变引入的缺陷等．研究表明，在原生半导体材料中存在各种缺陷，经过辐照和形变后有单空位、双空位及孔洞形成；在重掺杂材料中，空位还补偿载流子，使载流子发生饱和．

We briefly introduced our recent progress on the study of defects in Ⅲ -Ⅴ compound semiconductors using positron annihilation spectroscopy, they include: discrimination of the nature, size, charge state of defects in as-grown materials, study of negative ions, defect-impurity interaction, irradiation and deformation induced defects. The result showed that various defects exist in as-grown semiconductors; after ion-irradiation and deformation, not only monovacancy, but also divacancy and voids are formed; in heavily doped materials, the vacancy can compensate the free carriers, and cause carrier saturation.