Cost effective Dual-Junction CdTe Tandem Photovoltaic Devices with Enhanced Junctions

This proposal aims to develop highly efficient and low-cost monolithic tandem CdTe thin-film solar cells in a dual-junction configuration with enhanced junctions, utilizing an innovative ex-situ device annealing process. Tandem photovoltaic devices are emerging as a viable path to significantly improve the power conversion efficiency (PCE) >30 %, overcoming the limitation of current single-junction Si and CdTe devises. The Research Goal of this proposal is to develop dual-junction polycrystalline tandem CdTe devices by optimizing the film grain growth with enhanced laser device activation annealing processes. Additionally, using novel machine learning modeling techniques, we will extract parameters for a carrier dynamics model during device activation to understand the improvement mechanism. Using this understanding, we plan to maximize the grain growth of the film through optimized annealing processes for scale-up tandem device fabrication. The Research Objectives are as follows: i) Grow and optimize the CdTe tandem thin-film grain growth and junctions; ii) Refine a laser flash activation annealing process, and extract parameters of ML-augmentedcarrier collection of CdTe devices. This integrated multi-scale investigation aims to establish a new pathway for creating highly efficient and low-cost photovoltaic devices. Additionally, we intend to identify the crucial device activation process, which will provide valuable insights for developing strategies to enhance efficiency. Following this pilot support period, this proposal will lay the groundwork for seeking federal grants, including Department of Energy EPSCoR Implementation Grants, DE-FOA-3444 and Small Innovative Projects in Solar, DE-FOA-3308 to expand our research