Rapid Identification of Optimal Dopants for Silicon Based Broadband Infrared Detectors via Quantum Mechanical Simulation
Technical Report,01 Sep 2015,31 May 2016
University of Illinois - Urbana - Champaign Champaign United States
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We report our results of a systematic computational investigation to reveal the origin of and limitations to the subband gap optical absorption of Au-hyperdoped silicon. Doping silicon with non-equilibrium concentrations of atoms hyper-doping yields strong optical absorption reaching out to wavelengths in the short and towards the mid infrared regime. Despite this, in gold-hyperdoped materials photodiode response is weak and device quantum efficiencies are low. First-principles density functional theory was used to determine realistic defect structures of silicon hyperdoped with gold, and establish how the electronic structure of the material evolves with increasing defect concentration. The optical absorption of the material as a function of dopant concentration was be determined, and the reason for limited absorption identified as defect deactivation resulting from formation of defect clusters and precipitates. The proposed work complements currently on-going experimental efforts at ARDEC Benet Labs and U Dayton at synthesis and characterization of gold-hyperdoped silicon materials. The work will lay the foundation for further design and optimization of hyper-doped silicon materials as potential electronic sensors for the SWIR to the MWIR regime.
- Infrared Detection and Detectors