Author: Sebastian Bonilla, Associate Professor of Materials, University of Oxford

The sight of solar panels installed on rooftops and large energy farms has become commonplace in many regions around the world. Even in grey and rainy UK, solar power is becoming a major player in electricity generation. This surge in solar is fuelled by two key developments. First, scientists, engineers and those in industry are learning how to make solar panels by the billions. Every fabrication step is meticulously optimised to produce them very cheaply. The second and most significant is the relentless increase in the panels’ power conversion efficiency – a measure of how much sunlight can be transformed…