Chevallier Romain, Haddadi Abbas, Razeghi Manijeh
Center for Quantum Devices, Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, 2220 Campus Drive, RM 4051, Evanston, IL, 60208-0893, USA.
Sci Rep. 2017 Oct 3;7(1):12617. doi: 10.1038/s41598-017-13016-9.
Microjunction InAs/InAsSb type-II superlattice-based long-wavelength infrared photodetectors with reduced dark current density were demonstrated. A double electron barrier design was employed to reduce both bulk and surface dark currents. The photodetectors exhibited low surface leakage after passivation with SiO, allowing the use of very small size features without degradation of the dark current. Fabricating microjunction photodetectors (25 × 25 µm diodes with 10 × 10 µm microjunctions) in combination with the double electron barrier design results in a dark current density of 6.3 × 10 A/cm at 77 K. The device has an 8 µm cut-off wavelength at 77 K and exhibits a quantum efficiency of 31% for a 2 µm-thick absorption region, which results in a specific detectivity value of 1.2 × 10 cm·Hz/W.
展示了具有降低暗电流密度的基于微结InAs/InAsSb II型超晶格的长波长红外光电探测器。采用双电子势垒设计来降低体暗电流和表面暗电流。在用SiO₂钝化后，光电探测器表现出低表面泄漏，允许使用非常小尺寸的特征而不会使暗电流退化。结合双电子势垒设计制造微结光电探测器（25×25 µm二极管，带有10×10 µm微结），在77 K时暗电流密度为6.3×10⁻⁵ A/cm²。该器件在77 K时截止波长为8 µm，对于2 µm厚的吸收区域，量子效率为31%，这导致比探测率值为1.2×10¹¹ cm·Hz¹/²/W。
