Demonstration of a near and mid-infrared detector using multiple step quantum wells /
Abstract (Summary)In this thesis a device was designed to ultimately detect a laser designator operating at 1.06 æ m and infrared radiation near 10 æ m simultaneously. The final design consisted of 25 quantum step wells 80 æ m wide. The peak IR absorption coefficient was 1800 cm-1 at 11.1 æ m with a bandwidth of 1.6 æ m. Dark current was measured to be 1.6 x 10-8 A at 1 V bias at 10 K and a background photocurrent of 4.6 x 10-6 A at 10 K. The background-limited performance of the device occurs at approximately 55 K. The barrier height of the well was 99 meV. The maximum responsivity for each band was measured to be 0.04 A/W at 840 nm and 0.69 A/W at 10.93 æ m. Detectivity was then calculated to be 3.4 x 1010 cm Hz /W in the NIR band and 6.5 x 1011 cm Hz /W in the IR band. D* at the background limited point (D*BLIP) was 2.0 x 109 cm Hz /W in the NIR and 3.9 x 1010 cm Hz /W in the IR.
School Location:USA - California
Source Type:Master's Thesis
Keywords:quantum wells infrared detectors
Date of Publication: