First-principles study on electronic and optical properties of O-adsorbed Al0.5Ga0.5N photocathode surface

Liu, Lei; Lu, Feifei; Zhangyang, Xingyue; Cheng, Hongchang; Guo, Xin

doi:10.1016/j.apsusc.2023.156884

Cited by 1 publication

(1 citation statement)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To investigate the changes in optical features of the Al 0.5 Ga 0.5 N photocathode surface after activation, we analyze in detail the real parts of dielectric function, absorption coefficient, and reflectivity of pure, Cs-activated, Cs/O-activated, Cs/NF 3 -activated, and Cs/NF 3 /Li-activated Al 0.5 Ga 0.5 N thin films and nanowire surfaces. The calculation formulas are defined by − ε ( ω ) = ε 1 ( ω ) + i ε 2 ( ω ) α = 2 ω k c = 4 π k λ 0 R ( ω ) = false[ false( n − 1 false) 2 + k 2 false] false[ false( n + 1 false) 2 + k 2 false] where ε(ω) is the dielectric function and ε 1 (ω) and ε 2 (ω) are the real and imaginary parts of the dielectric function. α represents absorption coefficient, c is the speed of light in a vacuum, and λ 0 is the wavelength.…”

Section: Resultsmentioning

confidence: 99%

Comparison Study of Structural Stability and Optoelectronic Properties of Al_0.5Ga_0.5N Thin Film and Nanowire Photocathode Surfaces under Different Activation Methods

Tian,

Liu,

Zhangyang

et al. 2023

J. Phys. Chem. C

Self Cite

View full text Add to dashboard Cite

Different surface activation modes affect the performance and quantum efficiency of AlGaN-based photocathodes. According to first-principles-based calculations, we investigate the structural stability, charge transfer, band structure, density of states, dielectric function, absorption coefficient, and reflectivity of Al 0.5 Ga 0.5 N thin film and nanowire surfaces that are pure, Cs-activated, Cs/O-activated, Cs/NF 3 -activated, and Cs/ NF 3 /Li-activated in detail. Our results imply that the Al 0.5 Ga 0.5 N thin film surface is more easily activated by Cs/NF 3 , while the Al 0.5 Ga 0.5 N nanowire surface is more easily activated by Cs, and the activation process of the thin film is easier. After Cs activation, the band structure of the Al 0.5 Ga 0.5 N surface moves downward, and the Fermi level passes through the conduction band. The system has n-type conductivity, which also leads to a reduction of work function. When the activation process continues with the addition of O or NF 3 , conduction band minimum moves to a high-energy position, further reducing the work function, which is conducive to electron overflow and improving quantum efficiency. In addition, surface activation introduces new energy levels, mainly due to the hybridization of the s and p orbitals of activated atoms. The results of the optical properties imply that surface activation significantly enhances the optical performance of Al 0.5 Ga 0.5 N photocathodes.

show abstract

Section: Resultsmentioning

confidence: 99%

Comparison Study of Structural Stability and Optoelectronic Properties of Al_0.5Ga_0.5N Thin Film and Nanowire Photocathode Surfaces under Different Activation Methods

Tian,

Liu,

Zhangyang

et al. 2023

J. Phys. Chem. C

Self Cite

View full text Add to dashboard Cite

show abstract

First-principles study on electronic and optical properties of O-adsorbed Al0.5Ga0.5N photocathode surface

Cited by 1 publication

References 34 publications

Comparison Study of Structural Stability and Optoelectronic Properties of Al_0.5Ga_0.5N Thin Film and Nanowire Photocathode Surfaces under Different Activation Methods

Comparison Study of Structural Stability and Optoelectronic Properties of Al_0.5Ga_0.5N Thin Film and Nanowire Photocathode Surfaces under Different Activation Methods

Contact Info

Product

Resources

About

First-principles study on electronic and optical properties of O-adsorbed Al0.5Ga0.5N photocathode surface

Cited by 1 publication

References 34 publications

Comparison Study of Structural Stability and Optoelectronic Properties of Al0.5Ga0.5N Thin Film and Nanowire Photocathode Surfaces under Different Activation Methods

Comparison Study of Structural Stability and Optoelectronic Properties of Al0.5Ga0.5N Thin Film and Nanowire Photocathode Surfaces under Different Activation Methods

Contact Info

Product

Resources

About

Comparison Study of Structural Stability and Optoelectronic Properties of Al_0.5Ga_0.5N Thin Film and Nanowire Photocathode Surfaces under Different Activation Methods

Comparison Study of Structural Stability and Optoelectronic Properties of Al_0.5Ga_0.5N Thin Film and Nanowire Photocathode Surfaces under Different Activation Methods