InAs/Ga(In)SbⅡ类超晶格材料由于特殊的二型能带结构,可以通过人造低维结构获得类似于体材料的带间吸收,从而获得较高的量子效率;另外,通过调节材料参数调节能带结构,器件响应波段可调;通过能带结构设计抑制俄歇复合,获得较小的暗电流和较高的器件性能。因为以上特有的材料性能和器件特性,Sb基二类超晶格在国际上被认为是第三代红外焦平面探测器的优选材料。对二类超晶格材料的设计和器件特性进行了研究,设计了峰值波长4μm的nBn结构的中波红外探测器,在没有蒸镀抗反膜的条件下,77K温度下测试得到的峰值探测率为2.4×10^11cmHz^1/2W^-1,计算得到的量子效率为47.8%,峰值探测率已经接近目前的碲镉汞中波红外探测器器件性能。研究结果充分显示了二类超晶格优越的材料和器件性能。
InAs/Ga (In)Sb type-Ⅱ superlattices has been thought as the important third-generation infrared detectors, since the excellent material properties and devices performances, such as the high quantum coefficiency owing to band-to-band like absorption, the tunable wavelength response from the tunable energy band structure, the low dark current via the suppressed Auger recombination. Materials optimum design was studied to prepare the InAs/GaSb type-II mid-wavelength infrared detectors, nBn device structure was adoped to decrease surface leakage current. Then high performance mid-wavelength infrared detector was obtained, the peak detectivity was measured and D* =2.4 ×10n cmHz^1/ZW-1 at 77 K temperature, the corresponding quantum coefficiency 47.8% without anti-reflection film. The measured peak detectivity is comparable with the present HgCdTe mid-wavelength detectors, the study results reveal the superior devices performance of InAs/Ga (In)Sb type-II superlattices infrared detector as the novel infrared detectors.