Reinforced Electric Field for All‐Oxide‐Based Transparent Photovoltaics by Gradient Doping Profiles

The transparent photovoltaic (TPV) device offers onsite power production with greater freedom for integrated applications, in which doping strategy helps to boost device performance. This study explores the effects of gradient doping with titanium (Ti) in zinc oxide (ZnO) to enhance the TPV device performance. By implementing a negative slope in Ti concentration from the substrate to the surface (i.e., reverse‐graded doping), a significant reduction is demonstrated in recombination processes due to the reinforcement in the built‐in electrical field, resulting in an improved photovoltaic efficiency. Additionally, the devices exhibit an average visible transparency value of 68.4% across the 400–825 nm wavelength range, reaching a maximum power conversion efficiency value of 6.74% under 365 nm illumination. These findings underscore the potential of graded Ti‐doping in ZnO to optimize TPV devices for applications in building‐integrated photovoltaics and photo‐communication, contributing to advancements in sustainable energy technologies.