Double perovskite compounds (DPCs) have gained much more attention due to their versatile character in the fields of electronics and spintronics. Using density functional theory (DFT) we investigated the electronic, magnetic and optical properties of DPC La₂BB′O₆ where B = Cr, Sc and V and B′ = Co, Ni. The electronic band gaps suggest these compounds are half-metallic (HF) semiconductors in the spin-up channel and metallic in the spin-down channel. Magnetic properties suggest these are ferromagnetic in nature, so all DPCs are half-metallic ferromagnetic (HM-FM). Furthermore, the compound La₂CrCoO₆ shows outstanding electronic and optical properties, so it can be used in optoelectronic/spintronic devices.

The dielectric constant of CCTO materials can be as high as 10⁴, which makes it suitable for use in electronic devices but the high dielectric loss limits its application. In this paper, a series of Sr and Zr co-doped CCTO ceramics having the formula Ca_0.8Sr_0.2Cu₃Ti_4−xZr_xO₁₂ (x = 0.1, 0.2, 0.3, 0.4) were obtained via a solid-state reaction technique. We force the effect of the Zr content on the phase composition, microstructure, cationic valence states, impedance, and dielectric properties of the as-prepared ceramics to reduce dielectric loss. The results demonstrate that Sr and Zr co-doping increases dielectric constant and reduces dielectric loss simultaneously, and the maximum dielectric constant (1.87 × 10⁵, 1 Hz) and minimum dielectric loss (0.43, 10² Hz) are obtained when x = 0.3. Mixed Cu⁺/Cu²⁺ and Ti³⁺/Ti⁴⁺ valence states are observed to coexist in the co-doped material lattices, which promote dipole polarization, and thereby increase the dielectric constant of the ceramics. The dielectric properties of the materials are analyzed according to the internal barrier layer capacitance model, which elucidates the contributions of the grains and grain boundaries to dielectric performance. The maximum grain boundary resistance (3.7 × 10⁵ Ω) is obtained for x = 0.3, which contributes toward the minimum dielectric loss (0.43) obtained for this ceramic at a frequency less than 1 kHz. The average grain sizes of the samples decrease with increasing Zr content, which is the primary factor increasing the grain boundary resistance of the co-doped ceramics.

In current investigations the optoelectronic properties of perovskite structure-based (PSB) compounds are collected. The power conversion efficiency (PCE) dependency on device design and different transport layers are given in detail. The number of PSB compounds is taken into account as emerging materials for optoelectronic and spintronics applications. The electronic properties suggest that these PSB compounds have many properties starts from insulator to conductors and semiconductors. Furthermore, the best compounds for optoelectronic applications are suggested, which are organic-inorganic PSB (AMPbX3 (A=CH3NH3, X=Cl, Br, I) compounds, best for optoelectronic applications especially for solar cells.