Review on Practical Interface Engineering of Perovskite Solar Cells: From Efficiency to Stability

Abstract

Exceptionally high efficiencies for organic–inorganic hybrid perovskite solar cells (PSCs) have been achieved. However, their operational stability still needs to be improved. The intrinsic instability of halide perovskites caused by the presence of volatile organic cations, as well as the degradation of hybrid perovskites induced by the adverse permeation of environmental water (H2O)/oxygen (O2) and the undesired ion diffusion or migration are the major reasons. Beyond strengthening perovskites themselves, interface engineering is now regarded as a valid strategy to prolong device lifetime by preventing the undesired degradation pathways. This comprehensive review highlights the utilization of practical interface engineering for enhancing the efficiency and stability of organic–inorganic lead halide PSCs. First, the impacts of interface design on the energy‐level alignment and carrier dynamics are overviewed. Second, recent progresses on the development of interfacial materials for simultaneously achieving high efficiency and stability of PSCs are summarized. At last, the interfacial layer design principles along with future outlook of this rapidly developing field are discussed.

Realizing Reduced Imperfections via Quantum Dots Interdiffusion in High Efficiency Perovskite Solar Cells

“…Formation of charged vacancies at the surface and GBs are inevitable following high temperature thermal annealing (around 100 °C); a necessary step in the fabrication of OIHP solar cells. [ 30–32 ] Although numerous molecules have been proposed to reduce the interfacial ionic defects, judicious molecular design is still needed to enhance the passivating effects further. [ 33–36 ] In general, organic molecules with long alkyl chains are introduced by dissolving them in isopropyl alcohol (IPA) and depositing them in a post‐deposition treatment process.…”

Barrier Designs in Perovskite Solar Cells for Long‐Term Stability

“…[8] To further improve the efficiency and long-term stability of PSCs, researchers have explored various interlayers inserting into the basic "n-i-p" or "p-i-n" structure from the perspective of interface engineering. [9][10][11] Beyond the rapidly increased PCE, improving the device stability to meet the requirement of practical application remains as one of the major topics of PSCs development, since there is still a long distance from the required 20-25 years' operation lifetime for photovoltaic applications. [12] To date, many works have been dedicated to revealing failure mechanisms of PSCs.…”

Interfacial Modification through a Multifunctional Molecule for Inorganic Perovskite Solar Cells with over 18% Efficiency

“…Recently, several strategies have been reported on improving the V OC and FF of CsPbI 3 ‐based PVSCs, including vacuum thermal coevaporation, solvent‐controlled growth, dimension engineering, B‐site doping/alloying, additive loading, and so on. However, the V OC deficit and FF loss are mainly caused by the defects in bulk and surface/grain boundaries of inorganic perovskites and the mismatch of energy bands between perovskite and charge‐transporting layer (CTL) . Therefore, it would be ideal if novel dual‐functional materials can be applied to simultaneously passivate perovskite surface and promote better energy alignment to improve PVSC performance.…”