Current Status of Emerging PV Technologies: A Comparative Study of Dye-Sensitized, Organic, and Perovskite Solar Cells

Table 3

State-of-the-art materials, processes, and methods used for the development of PSCs.

Photoanodes	Hole-transporting layer and interfaces	Device architecture	Improved stability
Improved morphology: precursor solution aging, film annealing, and incorporation of additives	Organic hole-transporting layer (such as carbon and spiro-MeOTAD)	Single-junction perovskite solar cells	Mixed-cation systems (e.g., Rb and Cs), or mixed-halide and mixed-cation systems, retain 92% of PCE after 1000 h
Optimization of absorption layer crystallinity and film uniformity	Inorganic p-type semiconductor materials, e.g., CuI, NiO, CuSCN, and CuGaO2, up to 18.5% PCE	Perovskite/CIGS tandem cells: perovskite top cell fabricated on CIGS bottom cell; Up to 24.2% PCE	Interfacial layers with UV-stable materials (SnO2, ammonium chloride) retain 94% of efficiency after 1000 h
Lead-free PSCs: transition metals, alkaline-earth metals, rare-earth ions, and divalent metal cations (Ba^2+, Ca^2+, and Sr^2+)	Interface engineering and optimization (e.g., incorporation of benzenethiol molecules for increased charge transport)—20% PCE	Perovskite/Si tandem cells: top perovskite cell and bottom Si cell; Up to 29.5% PCE	Use of self-assembled monolayers as interfacial layers
Double lead-free perovskites (Cs2AgSbI6, Cs2BiAuBr6, and Cs2BiCuI6)	Energy level modification by introducing an interfacial layer, such as poly(ethylene oxide)	Mechanically stacked and monolithic tandem device architectures	Encapsulation: glass film/epoxy resin, polymer sealants (polyethylene terephthalate), and