Proton implantation for electrical insulation of the InGaAs/InAlAs superlattice material used in 8–15 μm-emitting quantum cascade lasers
Proton implantation for electrical insulation of the InGaAs/InAlAs superlattice material used in 8–15 μm-emitting quantum cascade lasers
Kirch, J. D.; Kim, H.; Boyle, C.; Chang, C.-C.; Mawst, L. J.; Lindberg Iii, D.; Earles, T.; Botez, D.; Helm, M.; von Borany, J.; Akhmadaliev, S.; Böttger, R.; Reyner, C.
Abstract
We demonstrate the conversion of lattice-matched InGaAs/InAlAs quantum-cascade-laser (QCL) active-region material into an effective current-blocking layer via proton implantation. A 35-period active region of an 8.4 μm-emitting QCL structure was implanted with a dose of 5 × 10^14 cm−2 protons at 450 keV to produce a vacancy concentration of ∼10^19 cm−3. At room temperature, the sheet resistance, extracted from the Hall measurements, increases by a factor of ∼240 with respect to that of an unimplanted material. Over the 160–320 K temperature range, the activation energy of the implanted-material Hall sheet-carrier density is 270 meV. The significant increase in room-temperature sheet resistance indicates that upon implantation deep carrier traps have been formed in the InAlAs layers of the superlattice. Fabricated mesas show effective current blocking, at voltages ≥10 V, up to at least 350 K. Thus, the implanted InGaAs/InAlAs superlattices are highly resistive to at least 350 K heat sink temperature. Such implanted material should prove useful for effective current confinement in 8–15 μm-emitting InP-based single-emitter QCL structures as well as in resonant leaky-wave coupled phase-locked arrays of QCLs.
Keywords: Quantum cascade lasers; Ion Implantation; Protons; Superlattices; Leakage currents; Carrier mobility
Beteiligte Forschungsanlagen
- Ionenstrahlzentrum DOI: 10.17815/jlsrf-3-159
Verknüpfte Publikationen
- DOI: 10.17815/jlsrf-3-159 is cited by this (Id 25201) publication
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Applied Physics Letters 110(2017), 082102
DOI: 10.1063/1.4977067
Cited 6 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-25201