Photovoltaic (PV) systems deliver green energy and have a major role to play in energy grid decarbonization. Until their complete life cycles have become as sustainable and circular as is practicable, however, PV systems have not reached their full potential. To reliably assess the current performance of PV life cycles, and to identify future opportunities and pathways towards achieving global sustainability and circular economy goals, rigorous life cycle sustainability assessment built upon a solid foundation of granular, physics-based data is needed. We present results from such an approach, using process simulation to analyse the life cycles of Silicon, Perovskite, and Silicon-perovskite tandem PV technologies, all of which include various metallurgical production and recycling processes. We compare these life cycles in terms of resource efficiency, carbon footprint, minimum sustainable module price and levelized cost of energy, and evaluate the responses of these to changes in closed-loop recycling rate, carbon pricing, module efficiency, and PV system lifetime. Results demonstrate the value of this detailed, integrated approach and highlight the trade-offs between resource consumption, environmental impact, and cost to be optimized for sustainable circular economy.