采用分子束外延工艺方法生长的 InAs/GaSb二类超晶格材料因其独特的能带断带结构, 极大地降低了俄歇复合暗电流, 且其较大的电子有效质量使得隧穿电流进一步降低, 因此超晶格材料成为国内外红外领域研究关注的重点。本文介绍的超晶格中长波双色探测器采用 npn背靠背结构, 阵列规模为 320×256, 像元中心距为 30 .m。其中测得 80 K温度下, -0.1 V偏压工作时中波 50%截止波长为4.5 .m, 0.17 V偏压工作时长波 50%截止波长为 10.5 .m, 对应的峰值量子效率为 45%、33%, 相应的暗电流密度为 5.94×10-7 A/cm2@-0.1 V、1.72×10-4 A/cm2@0.17 V, NETD为 16.6 mK、15.6 mK。

InAs/GaSb type-II superlattice material grown by molecular beam epitaxy(MBE) technology offers uniquebroken energy band structure which facilitates suppression of Auger recombination dark current, and the large electron effective mass in superlattice leads to a reduction of interband tunneling current further. Accordingly, the study of superlattice material becomes a major research emphasis at home and abroad. This paper introduces a mid-/long-wavelength dual band infrared focal plane array photodetector with npn architecture, the focal plane array had a format of 320×256 with a 30 .m pitch. Under 80 K with the operating bias of -0.1 V and 0.17 V, the 50% cut-off wavelength was 4.5 .m and 10.5 .m, and peak quantum efficiencies of 45% and 33% were realized. Dark current density values were 5.94×10-7 A/cm2@-0.1 V, 1.72×10-4 A/cm2@0.17 V, meanwhile, the focal plane array exhibited an NETD of 16.6 mK and 15.6 mK.