在InSb衬底上利用分子束外延生长了p-i-n结构的InAlSb/InSb材料, 通过在吸收层和接触层之间生长宽禁带的InAlSb势垒层, 验证了势垒层对耗尽层中暗电流的抑制作用。分别基于外延生长的InAlSb材料和InSb体材料, 借助标准工艺制备出二极管, 并对其电性能进行测量分析, 研究发现: 77 K温度时, 在-0.1 V的外偏电压下, p+-p+-n--n+结构和p+-n--n+结构InAlSb器件的反偏电流分别为3.4×10-6 A·cm-2和7.8×10-6 A·cm-2。基于p+-p+-n--n+结构研制的InAlSb二极管的暗电流保持在一个很低的水平, 这为提高红外探测器的工作温度提供了重要基础。

The InAlSb/InSb material of p-i-n structure was grown by Molecular Beam Epitaxy(MBE) on(100) InSb substrate. The current suppression effect of the barrier layer on the dark current was verified by growing a barrier layer with a wide gap between the absorber layer and the contact layer. The electrical properties of photodiode fabricated by InAlSb epitaxial material were compared with that of traditional InSb bulk material. When the external bias voltage is -0.1 V, the reverse bias current of p+-p+-n--n+ InAlSb device and p+- n--n+ InAlSb device is 3.4×10-6 A·cm-2 and 7.8×10-6 A·cm-2 at 77 K, respectively. The p+-p+-n--n+ InAlSb device suppresses the dark current at a very low level. It provides an important foundation for improving operating temperature of the infrared detector.