Performance Limits in Bifacial Tandem Solar Cell Modules for Multiple Configurations

Abstract

While bifacial tandem photovoltaic technology is promising as it is able to generate higher electrical power output by accessing illumination from both front and rear surfaces, a thorough investigation of the performance limits of bifacial tandems with different architectures/arrangements and under different conditions has not been explored. In this work, we present a comprehensive analytical framework based on the principle of detailed balance to assess the performance limits of bifacial tandems spanning multiple architectures, including unconstrained, current-matched (CM), and voltage-matched (VM) configurations. Our methodology explores the performance benefits of incorporating area-decoupled subcells across layers and examines the impact of different bandgap arrangements (monotonic and non-monotonic) on the performance. We show that having non-monotonic arrangement of bandgaps under optimal albedo conditions can significantly enhance the performance of bifacial tandems. In addition, we analyze the performance resilience of each configuration and bandgap arrangement to spectral variations induced by environmental factors such as shading, fluctuations in temperature, and albedo. This provides crucial design guidelines for the design, fabrication, and estimation of the performance limits of these solar cell architectures in different conditions.