Recent climate change is widely recognized to be driven primarily by greenhouse gas emissions from the use of fossil fuels, making renewable energy a key solution to mitigating global warming. Today, the maximum power conversion efficiency of solar cells has reached 47.6% using multi-junction architectures. To push this limit even further, researchers are exploring a wide range of approaches, including multiple exciton generation, infinite p–n junction concepts, photon management using metamaterials, and cryogenic control of charge carriers. In theory, alternative concepts may enable solar cells with efficiencies approaching 60%. However, translating these theoretical possibilities into practical technologies remains an enormous challenge. Why is it so difficult to develop solar cells with a 60% power conversion efficiency, and what scientific and technological breakthroughs will be essential to achieve this goal?