Strain modulating electronic band gaps and SQ efficiencies of semiconductor 2D PdQ2 (Q = S, Se) monolayer

Abstract

We studied the physical, electronic transport and optical properties of a unique pentagonal PdQ2 (Q = S, Se) monolayers. The dynamic stability of 2Dwrinkle like-PdQ2 is proven by positive phonon frequencies in the phonon dispersion curve. The optimized structural parameters of wrinkled pentagonal PdQ2 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-PdQ2 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) cm2 V−1 s−1 and 1518.81 (442.49) cm2 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 PdQ2 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-PdQ2 exhibits high optical absorption intensity in the UV region, up to 4.04 × 105 (for PdS2) and 5.28 × 105 (for PdSe2), which is suitable for applications in optoelectronic devices. Thus, the ultrathin PdQ2 monolayers could be potential material for next-generation solar-cell applications and high performance nanodevices.

Hinge-like Co2S3and Co2Te3Nanosheets: Promising Two-Dimensional Optical, Thermoelectric, and Spintronic Materials

“…As shown in Figure f, in the y direction, although the spin-down current has an increasing trend and the spin-up current shows an NDR under a bias of 1.2 V, the spin-up current (75 μA) is more than the spin-down current (53 μA) under a bias voltage of 2 V. On the whole, the Co 2 X 3 (X = S, Te) nanosheets have anisotropic transport properties. It is important to note that the current passing through the Co 2 X 3 (X = S, Te) nanosheets is higher than the current passing through many 2D structures such as MoS 2 , BP, Pd 2 Se 3 , penta-PdQ 2 (Q = S, Se), and Mn-doped blue-P. ,, As a result, the 2D Co 2 X 3 (X = S, Te) can be further investigated as a candidate for spintronic nanodevices.…”

Modulation of electronic bandgaps and subsequent implications on SQ efficiencies via strain engineering in ultrathin SnX (X = S, Se) nanowires

“…75 Also, an SQ efficiency of up to 33.94% was reported in the case of a strained penta-PdSe 2 monolayer recently. 108 Even in the case of ultrathin SnS NWs, the SQ efficiency swells up to 29.28% at À10% compressive strain and up to 31.71% at +10% tensile strain. These values of photovoltaic efficiencies are substantial improvements over the 25% efficiency of leadbased perovskites, minus the toxic traits of lead.…”

High‐performance piezoresistive sensors based on transfer‐free large‐area PdSe2 films for human motion and health care monitoring

“…Furthermore, PdSe 2 shows excellent flexibility and mechanical stability, PdSe 2 monolayer can withstand up to 17% and 19% strain along the x and y directions, respectively. 34 Most importantly, PdSe 2 exhibits a wide range of tunable bandgaps under strain, 35 suggesting that its conductivity will change significantly, and it may exhibit excellent piezoresistive properties. Despite this, fundamental strain-dependent piezoelectric properties and strain sensing devices for PdSe 2 are not yet fully explored, to the best of our knowledge.…”