This review provides detailed information on perovskite solar cell device background and monitors stepwise scientific efforts applied to improve device performance with time. The work reviews previous studies and the latest developments in the perovskite crystal structure, electronic structure, device architecture, fabrication methods, and challenges. Advantages, such as easy bandgap tunability, low charge recombination rates, and low fabrication cost, are among the topics discussed. Some of the most important elements highlighted in this review are concerns regarding commercialization and prototyping. Perovskite solar cells are generally still lab-based devices suffering from drawbacks such as device intrinsic and extrinsic instabilities and rising environmental concerns due to the use of the toxic inorganic lead (Pb) element in the perovskite (ABX₃) light-active material. Some interesting recommendations and possible future perspectives are well articulated.

Undoped and Pb²⁺-doped ultrafine cubic zinc aluminate (ZnAl₂O₄) hosts were successfully prepared at a relatively low temperature (~80 °C) using the sol–gel method. The concentration of Pb²⁺ was varied from 0 to 5 mol%. The TGA showed that the minimum annealing temperature required to obtain single phase ZnAl₂O₄ must be above 400 °C. The XRD data revealed that all the annealed samples were single phase crystalline structures and the estimated crystallites size were in the range of 21–30 nm in diameter. The FTIR results suggest that heat-treating can destroy some of the bonds. The surface morphology of the phosphors was influenced by the Pb²⁺ mol%. Undoped and Pb²⁺-doped ZnAl₂O₄ nanoparticles exhibit the violet emission at slightly different positions. The slight peak shifts suggests the possibilities that the luminescence centre can either be due to the defects level in the host or Pb²⁺ ions. The emission peaks at 390 and 399 nm are ascribed to the typical UV transitions ³P_0,1 → ¹S₀ in Pb²⁺ ion. At the higher Pb²⁺ mol%, the luminescence quenching behaviour occurs, which suggests that doping with Pb²⁺ ions is accompanied by the introduction of new defect sites that enhance non-radiative recombination of the excited electrons.