Physica Status Solidi B: Basic Solid State Physics

Hu, Qiu‐Bo; Wang, Zhen‐Hao; Xiao, Yi‐Peng; Fan, Yu‐Di; Meng, Yu‐Ke; Zhang, Yan‐Jie; Zhang, Xin‐Shuai; Wan, Zhong; Chen, Jin‐Long; Tang, Chun‐Juan; Li, Hao; Min, Zhi‐Yu; Wang, Xiao‐Fei

doi: 10.1002/pssb.202500610pmid: N/A

Lead‐free (1‐x)(0.65Bi0.5Na0.5TiO3‐0.35SrTiO3)‐xFe2O3 (BNST‐xF) ceramics (x = 0–0.08) were successfully synthesized via solid‐state reaction, aiming to develop environmentally friendly high‐performance energy storage materials. The study systematically reveals how Fe2O3 doping optimizes the functional properties of BNST‐based ceramics. All samples retained a pure perovskite structure with dense microstructures and clear grain boundaries. Notably, Fe2O3 doping significantly enhanced the energy storage density, relaxation behavior, and breakdown strength compared with pure BNST. At higher doping levels (x ≥ 0.06), an electric‐field‐induced phase transition occurred, accompanied by antiferroelectric‐like P–E hysteresis within 15–70 kV/cm, attributed to electric‐field‐regulated dipole ordering. Dielectric analysis identified two distinct relaxation mechanisms below and above x = 0.06, originating from polar nanoregions (PNRs) and oxygen vacancies (VOs), respectively. This study reveals the microscopic mechanism of doping‐induced phase transition and relaxation dynamics, providing a feasible strategy for designing high‐performance lead‐free energy storage ceramics.

Cui, Mengyang; Qi, Hongxing; Li, Qing

doi: 10.1002/pssb.202500444pmid: N/A

Dark current in silicon‐based blocked impurity band (BIB) infrared detectors has long been a critical limitation on device performance. This work proposes a chiral‐phonon‐assisted spin current model at interfaces to explain the parabolic‐like dark current behavior observed at low bias voltages. Concurrently, the space charge limited current (SCLC) theory is employed to elucidate the dark current generation mechanism across the entire operational voltage range.

Tiwari, Priyanshi; Singh, Sharanjeet; Kumar, Dileep; Gupta, Mukul; Yogi, Arvind Kumar; Rawat, Rajeev

doi: 10.1002/pssb.202500280pmid: N/A

This study of CePdSn1−xSbx (x = 0, 0.05, 0.15) polycrystalline compounds shows that with Sb substitution, unit cell volume increases, and antiferromagnetic transition temperature (TN) as well as the temperature of Kondo minima shifts to low temperature. This can be explained by the weakening of coupling between the conduction electron and the f‐electron (Jcf$J_{\text{cf}}$) due to the negative chemical pressure effect. The simulated temperature dependence of resistivity (ρ), considering electron‐phonon scattering and crystal electric field contribution from three doubly degenerate levels spaced at 90 and 200 K, reproduces the measured ρ(T) above Kondo minima. As per the scaling of isothermal magnetoresistance (MR) curves in the paramagnetic region, Kondo temperature is found to be 11 K for CePdSn. Isothermal MR at 3 K shows a hysteretic field‐induced transition, probably between two antiferromagnetic‐like states. With Sb substitution, the signature of field‐induced transition becomes weaker, and net MR becomes negative for x = 0.15.

Vyas, Shruti; Patidar, Manju Mishra; Kumar, Ashok; Singh, Satyendra; Venkatesh, R.; Saravanan, P.; Deshpande, Uday; Rawat, Rajeev; Sharath Chandra, L. S.; Ganesan, V.

doi: 10.1002/pssb.202500314pmid: N/A

Dy2Ti2O7 is a well‐known member of the pyrochlore family, having an exotic ground state like spin ice, as the weakly interacting Ising spins of each tetrahedron follow the two‐in, two‐out ice rule. A low‐temperature study to understand this novel ground state is carried out using heat capacity and magnetization with no noticeable magnetic ordering. Heat capacity shows a broad anomaly around 1 K, indicative of short‐range interactions. Residual entropy of the spin‐ice state in zero magnetic field is 1.36 JK−1 mol−1 which is close to the Pauling prediction. Kagome‐ice state is to be formed when a magnetic field is applied, and residual entropy is 0.56 JK−1 mol−1 between 0.3 Tand 0.6 T, which matches the literature. A magnetic field–temperature (H–T) phase diagram has been visualized for the spin‐ice configuration. Observation of small yet clear peak structures around 0.2 K may be assigned to the first‐order (gas–liquid) transition below 0.4 K inside the Kagome‐ice state.

Panda, Binodbihari; Rütter, Juliane; Heckötter, Julian; Aßmann, Marc Alexander

doi: 10.1002/pssb.202500366pmid: N/A

Rydberg excitons in the semiconductor Cu2O have been shown to be highly efficient in neutralizing and screening charged impurities, which is referred to as purification. In this manuscript, the dynamics of this process are investigated, using a pump–probe experiment with improved temporal resolution of 15 ns. The transient absorption of Rydberg excitons is analyzed and five different physical mechanisms that influence it are uncovered. Further, the impact of excitons and an electron–hole plasma on the purification process is compared.

Molina‐Orozco, Daniel S.; Pérez‐Walton, Santiago; López‐Giraldo, Francisco E.; Osorio‐Guillén, Jorge M.; Espinosa‐García, William F.

doi: 10.1002/pssb.202500344pmid: N/A

NaAg3$_{3}$O2$_{2}$ is investigated as a potential top‐cell material for tandem solar cell configurations. To assess its suitability, the structural, bonding, and electronic properties of this semiconductor are examined using density functional theory with the PBEsol exchange–correlation functional and the G0$_{0}$W0$_{0}$ approximation. The material crystallizes in an orthorhombic crystal structure (Ibam space group) and exhibits polar covalent bonding with a bulk modulus of 67.4 GPa. NaAg3O2 is found to be a direct (at Γ) semiconductor with a bandgap of 1.79 eV. The calculated dielectric and optical properties show that NaAg3$_{3}$O2$_{2}$ is transparent to low‐energy photons but exhibits a sharp increase in light absorption near its bandgap of 1.79 eV, reaching absorption coefficient as high as 105$\left(10\right)^{5}$  cm−1$^{- 1}$, motivating experimental synthesis and further investigation. The bandgap, combined with its bonding and optical characteristics, suggests its potential as a top‐cell material in tandem solar cell configurations.

Xiao, Xiangjiang; Wang, Jinfu; Li, Decong; Kang, Kunyong; Zhu, Hanming

doi: 10.1002/pssb.202500536pmid: N/A

Organic–inorganic lead halide perovskites have attracted extensive attention from researchers due to their excellent optoelectronic properties. However, the toxicity of lead limits their further development and practical applications. Here, the DFT + U method was employed to investigate the electronic structure and optical properties of ABX3 halide perovskites, aiming to screen potential absorption materials for solar cells. Through formation energy calculations, 23 stable structures were selected from 30 ABX3 halide perovskites. Among these 23 stable structures, 9 Sn/Ge perovskites (CsSnI3, LiSnI3, NaSnI3, KSnI3, RbSnI3, CsGeI3, NaGeI3, KGeI3, and RbGeI3) are p‐type direct semiconductors with high thermal stability, low effective mass, high absorption coefficient, and suitable bandgaps (1–1.5 eV). Notably, the absorption coefficients of Ge‐based perovskites are higher than those of Sn‐based perovskites. Specifically, the average absorption coefficient of CsGeI3 is 2.23 times that of CsSnI3, exhibiting excellent visible light utilization ability. Our calculation results can provide valuable guidance for the design of high‐efficiency inorganic lead‐free perovskite solar cells.

Pandey, Shekhar Chandra; Sharma, Shilpam; Chattopadhyay, Maulindu Kumar

doi: 10.1002/pssb.202500289pmid: N/A

Amorphous thin film superconductors are promising alternatives for the development of superconducting radiation detectors, especially superconducting nanowire single‐photon detectors and superconducting microwire single‐photon detectors, due to their homogeneous nature, ease of deposition, and superconducting parameters comparable to the materials currently being used. A study on the optimization of the growth technology and superconducting transition temperature (TC) of MoSi thin films grown on SiO2‐coated Si substrate is reported here. These films have been synthesized by cosputtering of Mo and Si targets with varying compositions and thicknesses to achieve optimized TC values close to that of the bulk. Mo80Si20 and Mo83Si17 compositions of the film, each with a thickness of 17 nm, exhibit the highest TC of 6.4 and 5.9 K, respectively. Additionally, a meander structure with a 17 μm wire width is patterned to estimate the transport critical current density (JC), which is measured to be 1.4 × 109 A m−2 at 4 K. Variation of the TC with film thickness and deposition pressure has been studied. Electrical resistance as a function of temperature of the film before and after meandering is also studied. These properties are compatible with the fabrication of superconducting nanowire, microwire, and wide strip single‐photon detectors.

Adoons, Vanthini Nelson; Molefe, Thandeka; Kotsedi, Lebogang; NtshaliNtshali, Delicacy; Yimamu, Ahmed Umer; Mosese, Setjhaba Victor; Masondo, Vusumuzi

doi: 10.1002/pssb.202500335pmid: N/A

In this study, undoped and Fe3+‐doped Ca2InTaO6 double perovskite samples are successfully synthesized by conventional high‐temperature solid‐state method. The influence of Fe doping on the structural, morphological, optical, and magnetic properties is systematically investigated. X‐ray diffraction patterns refined by the Rietveld method confirm a single‐phase orthorhombic structure (Pbnm space group) for all samples, with slight variations in lattice parameters and unit cell volume consistent with Fe3+ substitution at the In3+ site. Scanning electron microscopy reveals agglomerated, irregular particles, while energy‐dispersive X‐ray spectroscopy verifies the presence of Ca, In, Ta, Fe, and O in near‐stoichiometric proportions. UV–Vis analysis shows a progressive narrowing of the bandgap with increasing Fe content, attributed to the introduction of intermediate energy levels within the band structure. Photoluminescence spectra under 325 nm excitation exhibit a broad red emission at ≈671 nm due to Fe3+ 4T1(4G) → 6A1(6S) transitions, with intensity enhancement up to 10 mol% followed by concentration quenching. Magnetic hysteresis (M–H) curves indicates a transition from paramagnetic to weakly ferromagnetic behavior with increasing Fe3+ content, attributed to Fe–O–Fe superexchange interactions and spin canting. These findings demonstrate that Fe doping effectively tailors the multifunctional optical and magnetic properties of Ca2InTaO6 for potential photonic and spintronic applications.

Li, Liang; Yi, Zao; Cheng, Shubo; Tang, Chaojun; Gao, Fan; Li, Boxun

doi: 10.1002/pssb.202500447pmid: N/A

This article describles a new type of highly efficient solar absorber. The average absorption coefficient of this model under the condition of 1000 K temperature and within the spectral range of 280–3000 nm, which is as high as 97.9%, is obtained. Under the AM1.5 condition, the weighted average absorption rate of this model is as high as 97.8%. By analyzing the electric and magnetic field conditions of several absorption peaks, the high‐efficiency absorption of this model is not only limited to the materials it uses, but also related to the resonance caused by its geometric structure. This absorber has excellent thermal stability. It is found that this model has excellent thermal conversion efficiency performance and shows a continuous increase trend as the temperature rises. Using the control variable method to analyze, the adjustments of structural parameters of this model are obtained. Finally, the angle of the incident light is analyzed. The results show that the absorption rate of this model remains very high at different angles. Therefore, it is concluded that this model is angle insensitive. From the above analysis, it can be concluded that this model has an absolutely promising future application.