The role of extended and point defects, and key impurities such as C, O, and H, on the electrical and optical properties of GaN is reviewed. Recent progress in the development of high reliability contacts, thermal processing, dry and wet etching techniques, implantation doping and isolation, and gate insulator technology is detailed. Finally, the performance of GaN-based electronic and photonic devices such as field effect transistors, UV detectors, laser diodes, and light-emitting diodes is covered, along with the influence of process-induced or grown-in defects and impurities on the device physics.

Gan : processing, defects, and devices

Organo lanthanide metal complexes for electroluminescent materials.

Erbium doped materials are of great interest in thin film integrated optoelectronic technology, due to their Er3+ intra-4f emission at 1.54 μm, a standard telecommunication wavelength. Er-doped dielectric thin films can be used to fabricate planar optical amplifiers or lasers that can be integrated with other devices on the same chip. Semiconductors, such as silicon, can also be doped with erbium. In this case the Er may be excited through optically or electrically generated charge carriers. Er-doped Si light-emitting diodes may find applications in Si-based optoelectronic circuits. In this article, the synthesis, characterization, and application of several different Er-doped thin film photonic materials is described. It focuses on oxide glasses (pure SiO2, phosphosilicate, borosilicate, and soda-lime glasses), ceramic thin films (Al2O3, Y2O3, LiNbO3), and amorphous and crystalline silicon, all doped with Er by ion implantation. MeV ion implantation is a technique that is ideally suited to dope these materials with Er as the ion range corresponds to the typical micron dimensions of these optical materials. The role of implantation defects, the effect of annealing, concentration dependent effects, and optical activation are discussed and compared for the various materials.

Erbium implanted thin film photonic materials

Recent developments in rare-earth doped materials for optoelectronics

The vacuum arc is a rich source of highly ionized metal plasma that can be used to make a high current metal ion source. Vacuum arc ion sources have been developed for a range of applications including ion implantation for materials surface modification, particle accelerator injection for fundamental nuclear physics research, and other fundamental and applied purposes. The beam parameters can be attractive, and the source has provided a valuable addition to the spectrum of ion sources available to the experimenter. Beams have been produced from over 50 of the solid metals of the periodic table, with mean ion energy up to several hundred keV and with beam current up to several amperes. Typically the source is repetitively pulsed with pulse length of order a millisecond and duty cycle of order 1%, and operation of a dc embodiment has been demonstrated. Here the source fundamentals and operation are reviewed, the source and beam characteristics summarized, and some applications examined.

https://cds.cern.ch/record/1693045/files/p311.pdf

Vacuum Arc Ion Sources

Well‐resolved sharply structured luminescence spectra at 1.54 μm were observed in erbium‐implanted GaP, GaAs, InP, and Si. The optical transitions occur between the weakly crystal field split spin‐orbit levels, 4I13/2→4I15/2, of Er3+(4f11). Typical spectral linewidths in GaAs are 2 cm−1(0.25 meV) at 6 K and 11 cm−1(1.36 meV) at room temperature.

1.54‐μm luminescence of erbium‐implanted III‐V semiconductors and silicon

The feasibility of producing erbium‐doped silicon light‐emitting diodes by molecular beam epitaxy is demonstrated. The p‐n junctions are formed by growing an erbium‐doped p‐type epitaxial silicon layer on an n‐type silicon substrate. When the diodes are biased in the forward direction at 77 K they show an intense sharply structured electroluminescence spectrum at 1.54 μm. This luminescence is assigned to the internal 4f–4f transition 4I13/2→4I15/2 of Er3+ (4f11).

1.54‐μm electroluminescence of erbium‐doped silicon grown by molecular beam epitaxy

The characteristic 1.54‐μm emission from the rare‐earth element erbium implanted in GaAs, InP, and GaP was investigated through 10‐K photoluminescence essentially as a function of anneal temperature, time, and method. The strip‐heater, forming‐gas, and quartz‐ampoule anneal methods were utilized in the range of 400 to 1000 °C. Erbium‐related emissions were observed from 1.48 to 1.64 μm and were observable at emission temperatures of up to 260 K for InP:Er and 296 K for GaP:Er and GaAs:Er. Out of the three semiconductors, GaAs:Er was observed to exhibit the highest optical activation using a square‐profile implantation technique. Dependent on the anneal method, optimum Er emissions occurred between 650 and 800 °C for GaAs, for InP between 575 and 625 °C, and for GaP between 800 and 950 °C. In general, the forming‐gas anneal method proved most successful; however, maximum luminescence including sharper emission lines was achieved through the strip‐heater method. This method, with an anneal time of 10 s, sho...

Photoluminescence optimization and characteristics of the rare-earth element erbium implanted in GaAs, InP, and GaP

Rare earth activated luminescence in InP, GaP and GaAs

After implantation of ytterbium (Yb) in InP, GaP, and GaAs and subsequent annealing, we observed sharply structured photoluminescence bands at around 1.00 μm (1.24 eV). These emissions are assigned to the internal 4f‐4f transitions 2F5/2→2F7/2 of Yb3+ (4f13). Isochronal annealing studies and variations of the implantation dosages for Yb in InP were performed to optimize the luminescence efficiency and to decide whether there are different Yb centers responsible for the luminescence bands. It is shown that the dominant luminescence band arises from a cubic Yb3+ center which resides substitutionally on a cation site (In or Ga). Zeeman measurements and photoluminescence excitation spectroscopy further support this interpretation. The influence of electron irradiation on the luminescence efficiency of InP:Yb has been investigated. It is found that the Yb3+ luminescence intensity is only weakly affected, while the near band‐edge emission is strongly quenched.

Gernot S. Pomrenke

Papers

1.54‐μm luminescence of erbium‐implanted III‐V semiconductors and silicon

1.54‐μm electroluminescence of erbium‐doped silicon grown by molecular beam epitaxy

Photoluminescence optimization and characteristics of the rare-earth element erbium implanted in GaAs, InP, and GaP

Rare earth activated luminescence in InP, GaP and GaAs

Luminescence of the rare‐earth ion ytterbium in InP, GaP, and GaAs