Electrical and deep-level characterization of GaP1−xNx grown by gas-source molecular beam epitaxy

Abstract

We have investigated electrical properties and deep levels of n-GaP1−xNx (x=0%−0.62%) grown on (100) n-GaP substrates by gas source molecular beam epitaxy. The x-ray photoelectron spectroscopy results showed no significant effects on the chemical bonding status of the host Ga-P matrix by the incorporation of small amounts of N atoms. In the Raman spectra, the zone-edge GaP-like vibration was observed at 387 cm−1, originating from alloy disorder or local distortion of the GaP1−xNx lattice. The electrical properties of the GaP1−xNx surfaces were characterized using a Schottky contact structure. An ideality factor of 1.10–1.15 and a Schottky barrier height of 1.1 eV were obtained from the current-voltage characteristics of Ni∕GaP1−xNx diodes, indicating good interface quality. The thermal admittance spectroscopy clearly detected the Si donor level with an activation energy of 84±4 meV in GaP and GaP1−xNx. For the GaP1−xNx samples, we observed deep levels probably associated with N-induced defects such as N-N pairs, N clusters, and an N-containing complexes.

Impact of N Incorporation on VLS Growth of GaP(N) Nanowires Utilizing UDMH

“…Bright-field ( e ) and dark-field ( f ) TEM images show strong strain contrast along the line of the diagonal of SF-free region. Typical twist and splitting of Bragg line [63] in the large-angle convergent beam electron diffraction (LACBED) pattern in ( g ) confirms the presence of dislocation in the SF-free region (highlighted in dark cyan)…”

“…This causes relaxation of the momentum conservation rules and thereby allows zone-boundary longitudinal optical phonon scattering due to phonons at or near the X point [59, 61]. As the X mode steadily increases with the UDMH ratio, it can be concluded that the incorporation rises, too [61–63]. Unfortunately, the intensity of the X mode does not allow for a quantification of the N content, since its exact relation with the N content is unknown and strongly depends on measurement conditions.…”

Detection of Nonradiative Recombination Centers in GaPN by Combining Two‐Wavelength Excited Photoluminescence and Time‐Resolved Photoluminescence

“…The sample was immerged in liquid N 2 to avoid any temperature effect at the sample surface caused by AGE irradiation. [ 25 ] The dominant peak is at 2.10 eV in both cases of the IB and the CB excitations without any change in spectral shape. The small peak at 2.07 eV in the PL spectra is due to the phonon replica.…”

“…[21][22][23][24] Different research works suggest that the GaPN layer contains deep-level defects which are associated with nitrogen interstitials, vacancies, and N-related defects such as N-N pairs, N clusters, and N-related complexes. [25,26] The actual efficiency of IBSCs is determined by the competition of cascade photoexcitation rate via the IB, and other radiative and NRR rates with these NRR centers. For the development of GaPN alloybased IBSC devices, it is indispensable to understand the formation and properties of NRR centers and eliminate them during growth process.…”

Structural and Photoelectrochemical Properties of GaP Nanowires Annealed in NH3

“…Depending on the method of alloy preparation, a separate “local vibrational mode” near 500 cm –1 which shows resonance enhancement has been noted , and described as the vibrational frequency of isolated Ga–N bonds surrounded by Ga–P bonds . The observation of this mode typically requires a high concentration of N in the lattice and/or low temperatures ( T < 20 K). , The local vibrational mode was not observed in the GaP 1– x N x nanowires at any excitation wavelength (λ = 514, 633, and 785 nm). A related mode at 437 cm –1 for N 2 (rather than N) replacing P in the anionic sites in the lattice has also been speculated for related GaAs 1– x N x alloys but was also not observed in the Raman spectra for the GaP 1– x N x samples prepared here.…”