利用变频导纳谱研究了γ辐照前后Ｈｇ１－ｘＣｄｘＴｅ（ｘ＝０６）ｎ＋ｏｎｐ结中的深能级缺陷．辐照前其缺陷能级位置在价带上０１５ｅＶ，俘获截面σｐ＝２９×１０－１８ｃｍ２，缺陷密度Ｎｔ＝６５×１０１５ｃｍ－３，初步认为是Ｈｇ空位或与其相关的复合缺陷；经过１０４Ｇｙ的γ辐照后其能级变得更深，在价带上０１９ｅＶ，同时其俘获截面增加了近一个数量级，而缺陷密度基本上没有变化．γ辐照引入的这种能级变化最终使器件的性能（探测率）下降了１／２以上． The deep level defects in Hg1-xCdxTe (x = 06) n + onp junctions before and after γ-irradiation were studied by using variable frequency admittance spectroscopy. The defect level before irradiation was 015eV in valence band, σp = 29 × 10-18cm2 in capture cross section and Nt = 65 × 1015cm-3 in defect density, which was initially considered as Hg vacancy or its related complex After the γ-irradiation of 104Gy, its energy level becomes deeper, with a value of 019eV on the valence band. At the same time, its capture cross section increases by nearly an order of magnitude, while the defect density is almost unchanged. This level change introduced by gamma irradiation ultimately degrades the device performance (detection rate) by more than a factor of two.