# Progress in Improving Photovoltaics Longevity
## 1 Introduction  
The global deployment of photovoltaics (PV) has seen remarkable growth in the last few years, with cumulative capacity reaching 1.6 TW in 2023 from 1.2 TW in 2022 [1]. In 2023, almost 450 GW of new PV systems were installed globally, showing the sector's fast expansion despite challenges such as supply chain disruptions and fluctuating material availability and costs. This increase, expected to reach a capacity of 2.4 TW by 2025 [2], is driven by a combination of increasing demand for renewable energy sources to support the clean energy transition, technological advancements in photovoltaics properties such as more efficient solar cells, the declining costs of modules, and improved energy storage solutions. For example, the efficiency of solar cells has increased with modification techniques such as PERC (Passivated Emitter and Rear Cell) developed by Prof. [PERSON] and his team, which enhances light absorption and electron collection [3], novel cell architectures such as TOPCON (Tunnel Oxide Passivated Contact) with an innovative electroncollection mechanism [4], new cell structures such as SHJ (Silicon Heterojunction) [5], and module arrangements (half cells, bifacial) [6]. Moreover, the efficiency of photovoltaics is continuously increasing with emerging and novel tandem cells, with a trend to reach 30% efficiency by 2030 [7]. Although research efforts have been mainly focused on improving the efficiency of photovoltaics, PV longevity is also becoming critical in their massive deployment. As the number of solar installations grows globally, the volume of end-of-life panels also increases and will require extensive recycling management. It is estimated that 1.7-8 million tons by 2030 and 60-78 million tons by 2050 of solar panel waste will need to be addressed worldwide [8]. China, the United States, Japan, Germany, and India are estimated to be the top five PV panel waste countries, and concerns are raised about the management of waste PV modules in the realms of environmental preservation and resource recovery [9; 10; 11]. Despite the advancements in PV technology, several barriers hinder effective recycling and the overall sustainability of solar energy systems [12]. The complexity of dismantling integrated systems, coupled with the economic feasibility of recycling processes, presents significant challenges [13]. Currently, many recycling methods are still in developmental stages, and existing mechanical recycling processes often yield materials that lack the purity required for reuse in new PV products [13]. This situation is exacerbated by a lack of standardized procedures for end-of-life management, which can lead to inconsistencies in recycling practices across different regions [14]. Furthermore, the current market dynamics leading to lower module prices may discourage investment in recycling technologies and infrastructure. As a result, many countries are still developing policies to address the growing issue of solar panel waste, which complicates the transition to a circular economy in the solar sector [12; 15]. Research gaps persist in the fields of PV technology and recycling, particularly regarding the development of materials that enhance durability and facilitate easier recycling [12; 16]. Therefore, not only do efficient, economical, and environmentally friendly recycling technology systems need to be developed, but PV lifetimes must also be improved in order to reduce module waste and recycling needs. This necessitates a shift toward more durable materials and designs that can withstand environmental stresses while maintaining high efficiency over time. In particular, building-integrated photovoltaics (BIPV) must prioritize longevity to ensure their economic viability and effectiveness as components of the building envelope [17]. The integration of PV technology into building materials presents unique challenges, including the need for aesthetic compatibility and structural integrity, which can complicate maintenance and replacement strategies.