Inorganic and Hybrid Interfacial Materials for Organic and Perovskite Solar Cells

Abstract

As organic solar cells (OSCs) and perovskite solar cells (PVSCs) move closer to commercialization, further efforts toward optimizing both cell efficiency and stability are needed. As interfaces strongly affect device performance and degradation processes, interfacial engineering by employing various materials as hole transport layers (HTLs) and electron transport layers (ETLs) has been a very active field of research in OSCs and PVSCs. Among them, inorganic materials exhibit significant advantages in promoting device performance due to their excellent charge transporting properties and intrinsic thermal and chemical robustness. In this review, an extensive overview is provided of inorganic semiconductors such as copper‐based ones with emphasis on copper iodide and copper thiocyanate, transition metal chalcogenides, nitrides and carbides as well as hybrid materials based on these inorganic compounds that have been recently employed as HTLs and ETLs in OSCs and PVSCs. Following a short discussion of the main optoelectronic and physical properties that interfacial materials used as HTLs and ETLs should possess, the functionalities of the aforementioned materials as interfacial, charge transport, layers in OSCs and PVSCs are discussed in depth. It is concluded by providing guidelines for further developments that could significantly extend the implementation of these materials in solar cells.

A brief review of hole transporting materials commonly used in perovskite solar cells

“…To take advantage of dopant-free organic HTMs is helpful to improve the stability, while to utilize inorganic materials can be a more effective strategy. Inorganic HTMs usually have great advantages of simple preparation, good chemical stability, high hole mobility and low cost, which makes it a potential candidate for organic HTMs to be used in stable PSCs [75][76][77]. Table 3 shows the physicochemical properties of the common inorganic HTMs [31,78].…”

Engineering Copper Iodide (CuI) for Multifunctional p‐Type Transparent Semiconductors and Conductors

“…Owing to the high hole conductivity of CuI and the well‐aligned VBM with the emerging solar absorber layers, for example, methylammonium lead iodide (MAPbI 3 ) perovskite, CuI has been widely utilized as an inexpensive dopant or promising alternative to organic HTLs in organic or perovskite solar cells, leading to an enhanced power conversion efficiency (PCE) and stability. [ 15 , 152 , 153 , 154 , 155 ] The first attempt to incorporate CuI HTLs into solar cells was reported by Christians et al. in 2014.…”

Surfactant-Encapsulated Polyoxometalate Complex as a Cathode Interlayer for Nonfullerene Polymer Solar Cells

“…As we know, appropriate multifunctional CIL materials should possess enhanced hydrophobicity to mitigate moisture penetration and the associated water-induced degradation. [62][63][64] In order to further explain the improved stability of the NF-PSCs with…”