Conference Paper

Deep-level transient spectroscopy in InGaAsN lattice-matched to GaAs

Nat. Renewable Energy Lab., Golden, CO, USA
DOI: 10.1109/PVSC.2002.1190779 Conference: Photovoltaic Specialists Conference, 2002. Conference Record of the Twenty-Ninth IEEE
Source: IEEE Xplore

ABSTRACT Deep-level transient spectroscopy (DLTS) measurements have been performed on the quaternary semiconductor InGaAsN. A series of as-grown, metalorganic chemical vapor deposited samples having varying composition were grown and measured. A GaAs sample was used as a baseline for comparison. After adding only In to GaAs, we did not detect significant additional defects; however, adding N and both N and In led to larger hole-trap peaks and additional electron-trap peaks in the DLTS data. The samples containing about 2% N, with and without about 6% In, had electron traps with activation energies of about 0.2 and 0.3 eV. A sample with 0.4% N had an electron trap with an activation energy of 0.37 eV.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Triple-junction cells composed of III-V materials currently hold the world record for photovoltaic efficiency. In order to further increase cell efficiency in the future 4- and 5-junction cells incorporating a sub-cell with a bandgap of roughly 1.0 eV will be required. In this study 1.0 eV bandgap GaInNAs devices grown by solid source molecular beam epitaxy are investigated in terms of materials quality and device performance that show similar or better properties to the best MOVPE grown devices found in the literature. Deep-level transient spectroscopy measurements illustrate that the trap concentrations in the GaInNAs material are significantly lower than that of MOVPE grown material. The internal quantum efficiency (43%), open-circuit voltage (450 mV), short-circuit current density (25.76 mA/cm<sup>2</sup>) and fill-factor (56.4%) of the GaInNAs devices under 1-sun power density 1064 nm radiation are similar to or surpass the properties of the best MOVPE GaInNAs devices found in the literature.
    Photovoltaic Specialists Conference, 2005. Conference Record of the Thirty-first IEEE; 02/2005
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The dilute-nitride GaInNAs shows great promise in becoming the next choice for long-wavelength (0.9 to 1.6 mum) photodetector applications due to the ability for it to be grown lattice-matched on GaAs substrates. GaAs-based devices have several advantages over InP-based devices, such as substrate cost, convenience of processing, and optoelectronic band parameters. This paper will present results from the first high-quality thick GaInNAs films grown by solid state molecular beam epitaxy with a nitrogen plasma source and the first high efficiency photodetectors which have been fabricated from those materials. GaInNAs films up to 2 microns thick have been grown coherently on GaAs substrates. These films exhibit reasonable photoluminescence intensities at peak wavelengths of 1.22 to 1.13 mum before and after a rapid thermal anneal at a series of temperatures. PIN photodiodes with these thick GaInNAs films in the intrinsic regions show responsivity (better than 0.5 A/W at 1.064 mum), dark current (200 nA at -2 V), and signal-to-noise ratio (greater than 105) approaching those of commercially available InGaAs/InP devices. Furthermore, it will be shown that these devices show significantly lower dark current and higher signal-to-noise ratio than similar metamorphic InGaAs/GaAs structures.
    Proc SPIE 01/2005; 5726:27-34.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: SUMMARY We experimentally investigated terahertz photomixing op- eration at room temperature in an InGaP/InGaAs/ GaAs two-dimensional plasmon-resonant photomixer incorporating grating-bicoupled dual-gate structure. Photoelectrons drifting into a high-density plasmon cavity grat- ing from an adjacent low-density one extensively excite the plasmon reso- nance, resulting in emission of terahertz radiation. A vertical cavity formed between the two-dimensional plasmon grating plane and an indium-tin- oxide mirror at the back surface gains the radiation. Self-oscillation ini- tially at around 4.5 THz excited by a dc-photo carrier component was re- inforced by the photomixed differential-frequency excitation at 4.0 and 5.0 THz. This indicates a possibility of injection-locked oscillation of the photomixer in the terahertz frequency band.

Full-text (2 Sources)

Available from
Jul 7, 2014