Diffusion current characteristics of defect-limited nBn mid-wave infrared detectors
Abstract
Mid-wave infrared, nBn detectors remain limited by diffusion current generated in the absorber region even when defect concentrations are elevated. In contrast, defect-limited conventional pn-junction based photodiodes are subject to Shockley-Read-Hall generation in the depletion region and subsequent carrier drift. Ideal nBn-architecture devices would be limited by Auger 1 generation; however, typical nBn detectors exhibit defect-dominated performance associated with Shockley-Read-Hall generation in the quasi-neutral absorbing region. Reverse saturation current density characteristics for defect-limited devices depend on the minority carrier diffusion length, absorbing layer thickness, and the dominant minority carrier generation mechanism. Unlike pn-based photodiodes, changes in nBn dark current due to elevated defect concentrations do not manifest at small biases, thus, the zero bias resistance area product, RoA, is not a useful parameter for characterizing nBn-architecture photodetector performance.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 27, 2015
- Source ID
- 10.1063/1.4919450
Entities
People
- C. P. Morath
- D. E. Sidor
- G. R. Savich
- G. W. Wicks
- V. M. Cowan
- Xunsheng Du
Organizations
- Air Force Research Laboratory
- Army Research Office
- University of Rochester