Dr. A.P.J. Abdul Kalam Technical University (AKTU), before 2015 as the Uttar Pradesh Technical University (UPTU), is a state government run affiliating university in Lucknow, Uttar Pradesh, India. It was established as the Uttar Pradesh Technical University through the Government of Uttar Pradesh on 8 May 2000. To reduce workload and to ensure proper management, the university was bifurcated into separate universities, Gautam Buddh Technical University (GBTU) and Mahamaya Technical University (MTU), with effect from 1 May 2010. In 2013, as a new government came into power, the university was formed again by combining the two on 5 January 2013.It is an affiliating university, with approximately 800 colleges affiliated to it. The university was earlier on the IET Lucknow campus. Now it is in its newly inaugurated campus in Jankipuram, Lucknow. Additionally, the university had a Centre and Regional Office in Noida, Uttar Pradesh.Dr. A.P.J. A.P.J. A.P.J..
This study numerically investigates the potential application of cesium-based lead-free double perovskite solar cells. We systematically correlated bulk defect density, interface defect states, carrier lifetime, diffusion length, and band alignment effects within a unified optimization framework. For this, we investigated electrical parameters by optimizing the thickness, total defect density (Nt) and total interface defects (Ntf) of the absorber layer under standard AM 1.5G solar illumination light using SCAPS-1D software. The novel configuration Al/FTO/IGZO/Cs2AgBiBr6/GQDs/Au achieved power conversion efficiency (PCE) of 22.64
This study presents a comprehensive first-principles investigation of the structural, mechanical, electronic, optical, thermoelectric, and thermodynamic properties of half-Heusler PtTiZ (Z = Ge, Pb) compounds using the full-potential linearized augmented plane-wave (FP-LAPW) method combined with semiclassical Boltzmann transport theory. Exchange–correlation effects were treated within the LDA, PBE-GGA, and Tran–Blaha modified Becke–Johnson (TB-mBJ) schemes to achieve accurate electronic descriptions. Both alloys crystallize in a stable cubic F-43 m structure and exhibit indirect semiconducting behavior with band gaps of 0.66 eV (PtTiGe) and 0.387 eV (PtTiPb). The density-of-states analysis indicates that the valence region is dominated by Ti-3d and Z-p hybridized states, confirming strong p–d interactions. Mechanical stability criteria and positive elastic constants verify that both compounds are mechanically robust, with PtTiGe being stiffer and harder than PtTiPb. Optical results reveal pronounced absorption and high optical conductivity in the ultraviolet region, suggesting potential for optoelectronic applications. Thermoelectric analysis demonstrates p-type character with Seebeck coefficients of 229.21 µV K⁻¹ (PtTiGe) and 236.21 µV K⁻¹ (PtTiPb) at 300 K, and 235.05 µV K⁻¹ and 237.31 µV K⁻¹ at 1200 K, respectively. The corresponding lattice thermal conductivities decrease to 0.45 W m⁻¹ K⁻¹ and 0.32 W m⁻¹ K⁻¹, yielding maximum dimensionless figures of merit (ZT) of 0.68 and 0.70 at 1200 K. Thermodynamic results confirm that the Debye temperature increases with pressure while heat capacity decreases, ensuring stability at elevated conditions. Overall, the synergistic combination of electronic tunability, optical responsiveness, and favorable thermoelectric performance highlights PtTiZ (Z = Ge, Pb) as promising candidates for high-temperature thermoelectric and ultraviolet-optoelectronic applications.
Driven by the search for non-toxic alternatives to lead-based perovskites, this work presents a comprehensive first-principles investigation of novel gold-based halide perovskites, SrAuX3 (X = Cl, Br). Thermodynamic stability is confirmed through cohesive and formation energy calculations, with both compounds crystallizing in a stable cubic structure. Phonon dispersion calculations reveal no imaginary frequencies, confirming dynamical stability. Elastic constants satisfy Born stability criteria, and the calculated mechanical parameters indicate complementary behavior: SrAuCl3 exhibits high ductility (Pugh's ratio = 9.91), while SrAuBr3 shows greater shear rigidity (Shear Modulus = 12.86 GPa). Electronic property analysis reveals semiconducting behavior, with band gaps tuned by the halide identity: SrAuCl3 exhibits wider gaps (1.88-1.95 eV) ideal for visible-light absorption in photovoltaics, while SrAuBr3 has narrower gaps (0.70-1.44 eV) suitable for infrared optoelectronics. The materials demonstrate exceptional optical performance, including strong absorption from infrared to ultraviolet and high optical conductivity. Furthermore, they exhibit promising thermoelectric properties, with a figure of merit (ZT) reaching similar to 0.71 at high temperatures. This combination of compelling optoelectronic characteristics and efficient thermal energy conversion underscores the significant potential of SrAuX3 perovskites for applications in solar cells, light-emitting diodes, and high-temperature thermoelectric generators.
Cesium-based perovskites are gaining attention as non-toxic, thermally stable, and structurally robust materials for optoelectronic applications. In this work, we investigate Cs(2)ZAuF(6) (Z = In, Tl) using density functional theory (DFT) with PBE-GGA, TB-mBJ, and spin-orbit coupling (SOC). The computed elastic constants comply with Born's stability criteria, while hardness calculations indicate strong resistance to mechanical stress. Debye temperatures of 232.5 K and 186.7 K, and melting points of 1094 K and 1010 K for Cs2InAuF6 and Cs2TlAuF6, respectively, demonstrate high-temperature resilience. Electronic structure analysis shows direct bandgaps of 3.47 eV (Cs2InAuF6) and 1.06 eV (Cs2TlAuF6), suitable for ultraviolet optoelectronics, corroborated by substantial UV absorption. Thermoelectric assessments reveal high Seebeck coefficients (similar to 124 mu V/K and similar to 186 mu V/K), large power factors (similar to 11.4 x 10(10) W/mK(2)s at 250 K and 28 x 10(10) W/mK(2)s at 850 K), ZT values of 1.48 and 1.99, and low thermal conductivity for Cs2InAuF6 and Cs2TlAuF6, respectively, highlighting efficient energy conversion. Overall, Cs(2)ZAuF(6) (Z = In, Tl) emerge as promising candidates for advanced optoelectronic and thermoelectric devices.
Halide perovskites exhibit remarkable optoelectronic properties and compositional versatility, making them highly promising for next‐generation photovoltaics. This study investigates the photovoltaic potential of novel silver‐based halide perovskites AgAZ 3 (A = Ge, Sn; Z = Br, I) using the first‐principles method implemented in the WIEN2K code. Structural optimization, electronic band structure, density of states, and detailed optical spectra of these perovskite compounds were analyzed using the Tran–Blaha modified Becke–Johnson (TB‐mBJ) exchange–correlation potential. A comparative study of electronic properties was conducted with generalized gradient approximation (GGA)‐Perdew‐Burke‐Ernzerhof (PBE) and TB‐mBJ approaches. Structural integrity was validated via tolerance factor assessment and formation energy calculations. Density of states analysis (partial and total) identified atomic contributions. The optical properties of the compounds were evaluated by examining the real and imaginary components of the dielectric tensor, as well as reflectivity and refractive index spectra. The calculated direct bandgaps of AgGeBr 3 (1.07 eV), AgGeI 3 (0.97 eV), AgSnBr 3 (1.02 eV), and AgSnI 3 (0.81 eV) fall within the ideal range for photovoltaic applications, offering high theoretical efficiency potential and suitability for tandem or near‐infrared absorber cells. A diminution in bandgap is observed when substituting Br with I, and Ge with Sn, which also results in improved absorption efficacy. The outcomes demonstrate the strong potential of these perovskites for solar cell and optoelectronic applications. The outcomes theoretically demonstrate the strong potential of these perovskites for solar cell applications and provide a foundational roadmap for their experimental development.
