title: II-VI Quantum Cascade emitters in the 6-8μm range.
abstract: We present the growth and characterization of ZnCdSe/ZnCdMgSe quantum cascade (QC) heterostructures grown by molecular beam epitaxy (MBE) and designed to operate at 6-8μm. These structures utilize the better-understood ZnCdMgSe with InP lattice matched compositions yielding a bandgap of 2.80 eV as compared to previous work which used ZnCdMgSe compositions with bandgaps at 3.00 eV. Grown structures posses good structural and optical properties evidenced in X-ray diffraction and photoluminescence studies. Fabricated mesa devices show temperature dependent I-V measurements with differential resistance of 3.6 Ω, and a turn on voltage of 11V consistent with design specifications. Electroluminescence was observed in these devices up to room temperature with emission centered at 7.1 μm and line widths of ∼16%(ΔE/E) at 80K. The results show that these are well-behaved electroluminescent structures. Addition of waveguide layers and further improvements in well barrier interfaces are being pursued in efforts to demonstrate lasing.
authors.affiliation: Department of Chemistry, The City College of New York, 85 St. Nicolas Terrace, New York, New York 10031 USA; The Graduate Center, City University of New York, New York, New York 10016, USA.
authors.forename: Thor A
authors.initials: TA
authors.lastname: Garcia
authors.affiliation: Department of Physics, The City College of New York, 85 St. Nicolas Terrace, New York, New York 10031 USA; The Graduate Center, City University of New York, New York, New York 10016, USA.
authors.forename: Joel
authors.initials: J
authors.lastname: De Jesus
authors.affiliation: Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544 USA.
authors.forename: Arvind P
authors.initials: AP
authors.lastname: Ravikumar
authors.affiliation: Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544 USA.
authors.forename: Claire F
authors.initials: CF
authors.lastname: Gmachl
authors.affiliation: Department of Chemistry, The City College of New York, 85 St. Nicolas Terrace, New York, New York 10031 USA; The Graduate Center, City University of New York, New York, New York 10016, USA.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Tamargo
keywords: II-VI; Mid-IR; Quantum Cascade Lasers; Semiconductor Lasers