The solar power PV (solar photo-voltaic) technology has become one of the most critical renewable energy methods, to diminish the reliance on fossil fuel and to facilitate low carbon energy generation. In addition to installation capacity, other factors for large-scale PV system uptake include energy yield, conversion efficiency, operating reliability and sustainability of the PV systems’ lifecycle. This review presents a systematic analysis of salient materials, advanced device architectures and integrated system optimization techniques to enhance the efficiency of solar PV devices. Crystalline silicon, thin film, perovskite, tandem, organic, quantum-dot, two-dimensional, graphene-assisted and flexible PV materials are discussed. It also discusses heterojunction, PERC, bifacial, BIPV, floating and multijunction device architecture. The review on the system level encompasses Maximum Power Point Tracking, Cooling, Solar tracking, Artificial Intelligence, IoT Based monitoring and Performance Supervision. The results indicate that the most promising way forward for PV improvement is not by relying on a single technology, but by optimizing the PV system, from materials and device design to intelligent operation. Cost, stability, degradation, manufacturing scalability and long-term field reliability continue to be the primary challenges. Thus, durable high- efficiency tandems, smart monitoring, sustainable manufacturing of PV systems, and PV systems that are recyclable should be considered as areas of priority in future research.