Structural and luminescence properties of GaN nanowires grown using cobalt phthalocyanine as catalyst

Yadav, Shivesh; Rodríguez-Fernández, Carlos; Lima, M. M. de; Cantarero, A.; Dhar, Subhabrata

doi:10.1063/1.4937159

Cited by 13 publications

(13 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The blue shift occurred at slower rate over the temperature range studiedthis is commonly the case for published reports of the study of the temperature dependent blue shift of DAP peaks. [20,21] The temperature-dependent PL intensity of observed peaks in CuInSe 2 film with Cu/In = 0.80 was used to determine their thermal quenching behavior as depicted in figure 5b. The values of thermal activation energy of the DAP peak and its phonon replica obtained by using equation [21,22] were ~ 22 meV.…”

Section: Resultsmentioning

confidence: 99%

Identification of Defect Levels in Copper Indium Diselenide (CuInSe2) Thin Films via Photoluminescence Studies

et al. 2018

View full text Add to dashboard Cite

Photoluminescence (PL) spectroscopy has been used to study the defect levels in thin film copper indium diselenide (CuInSe2, CIS) which we are developing as the absorber layer for the bottom cell of a monolithically grown perovskite/CuInSe2 tandem solar cell. Temperature and laser power dependent PL measurements of thin film CIS for two different Cu/In ratios (0.66 and 0.80) have been performed. The CIS film with Cu/In = 0.80 shows a prominent donor-to-acceptor peak (DAP) involving a shallow acceptor of binding energy ∼22 meV, with phonon replica at ∼32 meV spacing. In contrast, PL measurement of CIS film for Cu/In = 0.66 taken at 20 K exhibited an asymmetric and broad PL spectrum with peaks at 0.845 eV and 0.787 eV. Laser intensity dependent PL revealed that the observed peaks 0.845 eV and 0.787 eV shift towards higher energy (aka j-shift) at ∼11.7 meV/decade and ∼ 8 meV/decade with increase in laser intensity respectively. The asymmetric and broad spectrum together with large j-shift suggests that the observed peaks at 0.845 eV and 0.787 eV were related to band-to-tail (BT) and band-to-impurity (BI) transition, respectively. Such a band-tail-related transition originates from the potential fluctuation of defect states at low temperature. The appearance of band related transition in CIS film with Cu/In = 0.66 is the indicator of the presence of large number of charged defect states.

show abstract

Section: Resultsmentioning

confidence: 99%

Identification of Defect Levels in Copper Indium Diselenide (CuInSe2) Thin Films via Photoluminescence Studies

et al. 2018

View full text Add to dashboard Cite

show abstract

“…11,14 In the past, several attempts were made to investigate the effect of native defects on various physical properties like stoichiometry, morphology, growth rate, and luminescence efficiency in GaN nanowires (NWs). [15][16][17][18][19][20] In our previous report, we have studied the effect of native defects on controlling the carrier concentration and mobility. 21 Spectroscopic techniques such as Raman, photoluminescence (PL) were utilized to understand the electron-phonon coupling as well.…”

Section: Introductionmentioning

confidence: 99%

Effect of Oxygen and Aluminum Incorporation on the Local Structure of GaN Nanowires: Insight from Extended X-ray Absorption Fine Structure Analysis

et al. 2021

View full text Add to dashboard Cite

A thorough investigation of local structure, influencing macroscopic properties of the solid is of potential interest.We investigated the local structure of GaN nanowires (NWs) with different native defect concentration synthesized by the chemical vapor deposition technique. Extended X-ray absorption fine structure (EXAFS) analysis and semi-empirical and the density functional theory (DFT) calculations were used to address the effect of dopant incorporation along with other defects on the co-ordination number and bond length values. The decrease of the bond length values along preferential crystal axes in the local tetrahedral structure of GaN emphasizes the preferred lattice site for oxygen doping. The preferential bond length contraction is corroborated by the simulations. We have also studied the impact on the local atomic configuration of GaN NWs with Al incorporation. AlxGa1-xN NWs are synthesized via novel ion beam techniques of ion beam mixing and post-irradiation diffusion process. The 2 change in the local tetrahedral structure of GaN with Al incorporation is investigated by EXAFS analysis. The analysis provides a clear understanding of choosing a suitable process for ternary III-nitride random alloy formation. The local structure study with the EXAFS analysis is corroborated with the observed macroscopic properties studied using Raman spectroscopy.

show abstract

“…The incorporation of native defects in GaN NWs can be due to growth process leading to the efficiency in the supply of precursor materials (Ga/N ratio), and crystallographic orientation. Several studies were carried out to realize the effect of supply of Ga/N ratio and O impurity incorporation on stoichiometry, size, surface morphology, growth rate, optical and electrical properties of GaN NWs [9][10][11][12][13]. Unlike in the case of thin films, it is difficult to perform measurements like secondary ion mass spectroscopy, Hall probe on single nanowires to quantify the concentration of native defects, resultant net carriers, and their mobility due to the nanowire geometry.…”

Section: Introductionmentioning

confidence: 99%

Spectroscopic investigation of native defect induced electron–phonon coupling in GaN nanowires

Parida¹,

Patsha²,

Bera³

et al. 2017

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

The integration of advanced optoelectronic properties in nanoscale devices of group III nitride can be realized by understanding the coupling of charge carriers with optical excitations in these nanostructures. The native defect induced electron-phonon coupling in GaN nanowires are reported using various spectroscopic studies. The GaN nanowires having different native defects are grown in atmospheric pressure chemical vapor deposition technique. X-ray photoelectron spectroscopic analysis revealed the variation of Ga/N ratios in nanowires having possible native defects, with respect to their growth parameters. The analysis of characteristics features of electron-phonon coupling in Raman spectra show the variations in carrier density and mobility with respect to the native defects in unintentionally doped GaN nanowires. The radiative recombination of donor acceptor pair transitions and the corresponding LO phonon replicas observed in photoluminescence studies further emphasize the role of native defects in electron-phonon coupling.

show abstract

Structural and luminescence properties of GaN nanowires grown using cobalt phthalocyanine as catalyst

Cited by 13 publications

References 45 publications

Identification of Defect Levels in Copper Indium Diselenide (CuInSe2) Thin Films via Photoluminescence Studies

Identification of Defect Levels in Copper Indium Diselenide (CuInSe2) Thin Films via Photoluminescence Studies

Effect of Oxygen and Aluminum Incorporation on the Local Structure of GaN Nanowires: Insight from Extended X-ray Absorption Fine Structure Analysis

Spectroscopic investigation of native defect induced electron–phonon coupling in GaN nanowires

Contact Info

Product

Resources

About