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- Raval, Dhara, et al.
(författare)
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Strain modulating electronic band gaps and SQ efficiencies of semiconductor 2D PdQ(2) (Q = S, Se) monolayer
- 2022
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- We studied the physical, electronic transport and optical properties of a unique pentagonal PdQ(2) (Q = S, Se) monolayers. The dynamic stability of 2Dwrinkle like-PdQ(2) is proven by positive phonon frequencies in the phonon dispersion curve. The optimized structural parameters of wrinkled pentagonal PdQ(2) are in good agreement with the available experimental results. The ultimate tensile strength (UTHS) was calculated and found that, penta-PdS2 monolayer can withstand up to 16% (18%) strain along x (y) direction with 3.44 GPa (3.43 GPa). While, penta-PdSe2 monolayer can withstand up to 17% (19%) strain along x (y) dirrection with 3.46 GPa (3.40 GPa). It is found that, the penta-PdQ(2) monolayers has the semiconducting behavior with indirect band gap of 0.94 and 1.26 eV for 2D-PdS2 and 2D-PdSe2, respectively. More interestingly, at room temperacture, the hole mobilty (electron mobility) obtained for 2D-PdS2 and PdSe2 are 67.43 (258.06) cm(2) V-1 s(-1) and 1518.81 (442.49) cm(2) V-1 s(-1), respectively. In addition, I-V characteristics of PdSe2 monolayer show strong negative differential conductance (NDC) region near the 3.57 V. The Shockly-Queisser (SQ) effeciency prameters of PdQ(2) monolayers are also explored and the highest SQ efficeinciy obtained for PdS2 is 33.93% at -5% strain and for PdSe2 is 33.94% at -2% strain. The penta-PdQ(2) exhibits high optical absorption intensity in the UV region, up to 4.04 x 10(5) (for PdS2) and 5.28 x 10(5) (for PdSe2), which is suitable for applications in optoelectronic devices. Thus, the ultrathin PdQ(2) monolayers could be potential material for next-generation solar-cell applications and high performance nanodevices.
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| 2. |
- Raval, Dhara, et al.
(författare)
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Ultrahigh carrier mobility and light-harvesting performance of 2D penta-PdX2 monolayer
- 2021
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Ingår i: Journal of Materials Science. - : Springer Nature. - 0022-2461 .- 1573-4803. ; 56, s. 3846-3860
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we have examined the geometrical, electronic and optical properties of penta-PdX2 (X = As,P) using density functional calculation. The electronic structure calculations show that the penta-PdAs2 and PdP2 are semiconductors with direct band gaps of 0.34 eV and 0.30 eV, respectively. The dynamical stability of penta-PdX2 monolayer is proved by the absence of imaginary frequencies in the phonon dispersion curve. By applying a biaxial strain (for PdAs2: - 6% to + 6% and for PdP2: - 5.5% to + 5.5%) on the monolayer, the effective mass and band edges are tuned effectively. Remarkably, the range of penta-PdX2 carrier mobility was obtained in an extremely high order of 10(5) cm(2) V-1 s(-1) for holes and 10(4) cm(2) V-1 s(-1) for electrons. The optical properties of penta-PdX2 were also strained-tunable and exhibit outstanding absorption of infrared, visible and ultraviolet light. More importantly, the band edges alignment has tunable with implemented external electric field (V/angstrom) along the z-direction. Our work would stimulate the fabrication of penta-PdX2 monolayer, and it is envisioned that it is an appropriate future candidate for optoelectronic and ultra-fast electronic applications.
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