Luminescence study of ZnTe:Cr epilayers grown by molecular-beam epitaxy
- 70 Downloads
Incorporation of Cr into ZnTe epilayers grown by molecular-beam epitaxy (MBE) is reported. Photoluminescence (PL) using both continuous wave (CW) and pulsed-excitation sources is used to characterize the radiative efficiency of doped layers in the infrared region. The Cr2+ ions produce a broad emission band peaking in the 2–3 µm range, which is of potential use in tunable-laser devices. The optimum Cr concentration for achieving bright, room-temperature infrared emission was found to be in the range from low- to mid-1018 cm−3. Temperature-dependent luminescence studies were performed to determine thermal-quenching activation energies. Using a pulsed-laser operating at 1.9 µm, an investigation of emission lifetimes was made. The emission-decay curves for the Cr2+ recombination in ZnTe:Cr films could be described by a single exponential and were nearly independent of temperature from 80 K to 300 K. A room-temperature lifetime of ∼2.5 µsec in a ZnTe:Cr layer with [Cr] ∼1.4 × 1018 cm−3 compares favorably with values reported for bulk ZnTe:Cr.
Key wordsZnTe ZnTe:Cr molecular-beam epitaxy (MBE)
Unable to display preview. Download preview PDF.
- 2.T.J. Carrig, Laser Focus World 38, 75 (2002).Google Scholar
- 5.R.S. Title, Phys. Rev. 133, A1613 (1964).Google Scholar
- 6.J. Dziesiaty, P. Peka, M.U. Lehr, A. Klimakow, S. Muller, and H.-J. Schulz, Z. Phys. Chemie 201, 63 (1997).Google Scholar
- 8.B.L. VanMil, A.J. Ptak, L. Bai, L. Wang, M. Chirila, N.C. Giles, T.H. Myers, and L. Wang, J. Electron. Mater. 31, 770 (2002).Google Scholar