Solar Cell Technology: Innovations and Challenges in Renewable Energy Conversion

Abstract

Photovoltaic (PV) technology has evolved from a niche, high-cost energy source into the fastest-growing generation technology in the global electricity mix, with cumulative installed capacity surpassing the terawatt scale by the mid-2020s. This review synthesizes the state of the art across the major solar cell technology families— crystalline silicon (c-Si), thin films (CdTe, CIGS), and emerging concepts (perovskites, organic photovoltaics, dye-sensitized cells, quantum dots, and tandem architectures)— with attention to device physics, materials innovation, manufacturing scalability, and sustainability. Crystalline silicon, now dominated by passivated-contact architectures such as TOPCon and heterojunction (HJT) cells, continues to approach its practical efficiency ceiling near the Shockley–Queisser limit, while thin-film CdTe and CIGS modules offer lower embodied energy and complementary spectral and mechanical properties. The most consequential recent advances lie in perovskite photovoltaics, where single-junction laboratory efficiencies now exceed 26% and perovskite/silicon tandem cells have surpassed 33%, offering a credible pathway beyond the singlejunction efficiency ceiling. Nonetheless, perovskites' operational stability, hysteresis, ion migration, and lead content remain unresolved barriers to bankable deployment at scale. Organic photovoltaics and dye-sensitized cells retain niche advantages in flexibility, transparency, and low-light performance but lag in efficiency and long-term durability. This review discusses the materials and interface engineering strategies— defect passivation, bandgap tuning, self-assembled monolayers, and two-dimensional capping layers—that have driven recent efficiency gains, alongside manufacturing innovations including roll-to-roll and slot-die coating, and integration concepts such as building-integrated photovoltaics (BIPV), agrivoltaics, and floating PV. Critical challenges are examined in depth: the efficiency–stability trade-off, supply constraints on indium, tellurium, and silver, degradation mechanisms and accelerated testing protocols, end-of-life recycling, and the soft costs that increasingly dominate total system economics. We conclude with an outlook on pathways toward >30–40% commercial module efficiencies via tandem and multi-junction architectures, the growing role of artificial intelligence and machine learning in accelerated materials discovery, and the research priorities that will determine whether photovoltaics can meet the multi-terawatt annual deployment rates required for a low-carbon energy system.