Study of Defect Levels in InAs/InAsSb Type-II Superlattice Using Pressure-Dependent Photoluminescence
Abstract
We have performed pressure-dependent PL measurements on an InAs/InAs0.86 Sb0.14 T2SL structure. By fitting the measured peak energy shift and observing a quenching of the PL intensity we have determined a crossover pressure at which we believe the T2SL electron confined state reaches that of a defect level in the superlattice. This change in nature from a radiative to non-radiative recombination mechanism with pressure is confirmed from power dependent PL measurements. We also examined the thermal activation energies atambient pressure and close to the crossover pressure. These results support and are consistent with the determined values for the pressure coefficients of the valence and conduction band edges of the structure and the defect level. As a result, these experiments provide strong evidence that the defect level is approximately 180 meV above the conduction band edge of InAs. Consequently, these findings explain why Ga-free T2SL structures have much longer minority carrier lifetimes, a highly desirable advantage for both mid-wave and long-wave IR photodetector applications.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 07, 2015
- Accession Number
- AD1001384
Entities
People
- Yong-hang Zhang
Organizations
- Arizona State University