The regioregularity and band gap of P3HT, an organic solar cell donor polymer, were improved. Oxidative coupling enhanced regioregularity, voltammetric p-doping broadened the optical absorption band and a molar mass increase reduced the band gap.

The rapid development of photovoltaic technology has driven the search for novel materials that can improve the cost-effectiveness and efficiency of solar cells. Organic semiconductors offer unique optical tunability and transparency, allowing customization for the absorption of specific optical spectra like near-infrared radiation. Through the molecular engineering of electron donors and acceptors, these materials can be optimized for targeted optical selectivity. This adaptability enables the development of efficient energy-harvesting devices tailored for specific spectral regions. Consequently, organic semiconductors present a promising avenue for specialized applications such as semi-transparent organic solar cells. This review offers a detailed summary of the latest developments in novel organic semiconductor materials, focusing on design principles and synthesis of materials in the context of semi-transparent organic solar cells. Optimization of molecular architecture, photovoltaic performance, and the optoelectronic properties of these materials has been explored, highlighting their potential for next-generation solar energy conversion.

Organic solar cells offer benefits such as transparent characteristics, affordability in manufacturing, and the ability to tailor light absorption properties according to specific needs. This review discusses challenges and recent strategies to enhance the power conversion efficiency of organic solar cells, such as bandgap tuning, molecular orbital alignment, active layer morphology engineering, electron-donating and -withdrawing group incorporation, side chain length engineering, a third additive’s insertion, and control of the solubility of materials. The good transparency of organic solar cells makes them ideal for greenhouse-integrated photovoltaics applications. By efficiently absorbing sunlight for photosynthesis and clean energy production, transparent organic solar cells optimize light management, enhance energy efficiency, and minimize overheating risks, resulting in more sustainable and efficient greenhouse operations. This review also evaluates organic solar cell integration in the greenhouse. The implementation of the strategies explored in this review can significantly impact a wide range of performance parameters in organic solar cells. These parameters include the optoelectronic properties, absorption spectrum, open circuit voltage, exciton dissociation, charge transport, molecular packing, solubility, phase separation, crystallinity, nanoscale morphology, and device stability. An optimized organic solar cell design is particularly beneficial for greenhouse-integrated photovoltaics, as it ensures efficient energy conversion and energy management, which are crucial factors in maximizing the performance of the greenhouse.