Biomass‐Derived Materials for Interface Engineering in Organic/Perovskite Photovoltaic and Light‐Emitting Devices

Abstract Compared to their inorganic counterparts, organic optoelectronic devices receive considerable attention due to their lower cost, mechanical flexibility, bandgap engineering, and solution processability. In particular, achieving sustainability in solar cells and light emitting devices is an important milestone in the development of green electronics. This has facilitated a close collaboration between different technological fields, opening new ways for low‐cost production and application of biomaterials. Recently, biomass materials, mainly derived from plants, animals and microorganisms, have emerged as effective candidates to modify the interfacial properties, and thus enhance the performance, lifetime, and stability of organic solar cells (OSCs), perovskite solar cells (PVSCs), and organic light‐emitting diodes (OLEDs). Compared to the commonly used synthetic interfacial materials, the use of biomass interlayer materials (BIMs) is still in its embryonic stages; however, their nontoxicity, biorelevance, sustainability, special proton conductivity, and rich functional groups are stimulating researchers around the globe to fabricate novel devices with improved efficiency. Herein, a comprehensive review of BIMs and their importance in next‐generation optoelectronic devices is provided. A well‐targeted comparison between the electrical and physical properties of different BIMs is provided, and how such characteristics improve the performance of three key optoelectronic devices: OSCs, PVSCs and OLEDs, is discussed.