Electronic structure of Zn doped Ga0.5Al0.5As photocathodes from first-principles

Yu, Xiaohua; Ge, Zhonghao; Chang, Benkang; Wang, Meishan

doi:10.1016/j.ssc.2013.03.032

Cited by 7 publications

(3 citation statements)

References 19 publications

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“…Figure 4(a) provides the work function of metal-adsorbed GaAs nanowire surfaces. The calculated work function for pure nanowire surface is 4.61 eV, which agrees with previous reported value [38]. After the incorporation of one metal atom, the work function are respectively cut down by 0.04 eV, 0.22 eV, 0.34 eV for Pt-, Ag-, Al-adsorbed surfaces, and conversely increased by 0.02 eV for Au-covered surface.…”

Section: Resultssupporting

confidence: 90%

Adsorption mechanism of Pt, Ag, Al, Au on GaAs nanowire surfaces from first-principles

Diao¹,

Liu²,

Xia³

2019

J. Phys.: Condens. Matter

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The electronic and optical properties of metal (M) atoms adsorbed GaAs nanowires are systemically investigated utilizing first-principles calculations based on density functional theory. Different materials (M = Pt, Ag, Al and Au) and different coverages (1M, 2M, 3M and 4M) are considered to construct surface adsorption models. The calculations show that all metal-adsorbed GaAs nanowire surfaces are stable, and the difficulty of metal atom adsorption on nanowire surfaces follows the rule of Ag > Au > Al > Pt. In addition, the layer distance variation of nanowire surfaces after metal atom adsorption mainly take place near the outmost layer region. In 1M coverage case, the work function is reduced by Pt, Ag, Al adsorption, while increased by Au adsorption. Specially, Pt-and Al-adsorbed GaAs nanowire surfaces are direct band gap semiconductors, but Ag-and Au-adsorbed surfaces are indirect band gap. The adsorption of metals on GaAs nanowire surfaces are via chemisorption. Moreover, metal atom adsorption can enlarger the absorption coefficient of GaAs nanowires, which are gradually enhanced with increasing the coverage of metal atoms.

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Section: Resultssupporting

confidence: 90%

Adsorption mechanism of Pt, Ag, Al, Au on GaAs nanowire surfaces from first-principles

Diao¹,

Liu²,

Xia³

2019

J. Phys.: Condens. Matter

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“…The calculated numerical change of electronic parameters is provided in Figure D‐F, respectively. The work function of the Zn‐doping GaAs nanowire is 4.34 eV, consistent with the previous reported value . The built nanowire surface model belongs to the heavy p‐type doping structure, resulting in the Fermi level is closer to VBM.…”

Section: Resultssupporting

confidence: 89%

“…The work function of the Zn-doping GaAs nanowire is 4.34 eV, consistent with the previous reported value. 33 The built nanowire surface model belongs to the heavy p-type doping structure, resulting in the Fermi level is closer to VBM. When only Cs atoms are adsorbed on the p-type nanowire surface, both CBM and VBM have an obvious shift toward the lower energy region until Cs coverage reaches 3Cs; afterwards, all band energy levels start to move upward.…”

Section: Resultsmentioning

confidence: 99%

Comparative study of negative electron affinity GaAs nanowire photocathodes with Cs/O and with Cs/NF₃from first‐principles

2019

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Summary We perform a detailed comparative study of Cs/O and Cs/NF3 activation mechanism of negative electron affinity (NEA) GaAs nanowire photocathodes through first‐principles calculations based on density functional theory (DFT). The adsorption energy, Mulliken charge distribution, work function, electron affinity, and dipole moment are analyzed. Results show that the stability of Cs/NF3 co‐adsorption nanowire surface is stronger than that of the Cs/O model. The incorporation of O or NF3 on Cs‐covered nanowire surfaces leads to a sharper decline of surface work function. The NEA states can be attained with both O2 and NF3. However, during the Cs/O activation process, it needs to strictly control the Cs/O ratio to achieve the maximum photoemission properties of cathode. Moreover, the work function variation of GaAs nanowire photocathodes activated with Cs, O, and NF3 can be explained by the dipole moment model. This work is expected to provide a theoretical guide for improving Cs/O and Cs/NF3 activation procedure for NEA GaAs nanowire photocathodes.

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Theoretical study on electronic and optical properties of Zn-doped In0.25Ga0.75As photocathodes

Jin

Chang

Guo

et al. 2015

Opt Rev

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Electronic structure of Zn doped Ga0.5Al0.5As photocathodes from first-principles

Cited by 7 publications

References 19 publications

Adsorption mechanism of Pt, Ag, Al, Au on GaAs nanowire surfaces from first-principles

Adsorption mechanism of Pt, Ag, Al, Au on GaAs nanowire surfaces from first-principles

Comparative study of negative electron affinity GaAs nanowire photocathodes with Cs/O and with Cs/NF₃from first‐principles

Theoretical study on electronic and optical properties of Zn-doped In0.25Ga0.75As photocathodes

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Electronic structure of Zn doped Ga0.5Al0.5As photocathodes from first-principles

Cited by 7 publications

References 19 publications

Adsorption mechanism of Pt, Ag, Al, Au on GaAs nanowire surfaces from first-principles

Adsorption mechanism of Pt, Ag, Al, Au on GaAs nanowire surfaces from first-principles

Comparative study of negative electron affinity GaAs nanowire photocathodes with Cs/O and with Cs/NF3from first‐principles

Theoretical study on electronic and optical properties of Zn-doped In0.25Ga0.75As photocathodes

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Comparative study of negative electron affinity GaAs nanowire photocathodes with Cs/O and with Cs/NF₃from first‐principles