Bypassing the Single Junction Limit with Advanced Photovoltaic Architectures

Area of Science:

• Photovoltaics and Renewable Energy
• Materials Science and Engineering
• Computational Physics

Background:

• Multijunction devices and photon up/down-conversion aim to exceed single-junction solar cell efficiency limits.
• Integrating these concepts faces challenges in processing, microstructure control, and spectral resilience.
• Existing models lack the capability to predict the performance of such integrated advanced photovoltaic architectures.

Purpose of the Study:

• To develop a predictive simulation environment for optimizing integrated photovoltaic architectures.
• To virtually optimize the electrical performance of multi-junction devices combined with photon conversion.
• To explicitly account for microstructure effects on performance in advanced solar cell designs.

Main Methods:

• A simulation environment based on Bayesian optimization was developed.
• Machine-learned predictive models, derived from high-throughput experimentation, were used to incorporate microstructure effects.
• The environment was applied to predict and optimize both vertical and lateral multi-junction architectures with photon conversion.

Main Results:

• Two novel photovoltaic architectures, a vertical "staggered half octave system" and a lateral "overlapping rainbow system," were identified.
• These architectures demonstrate potential to surpass the single-junction efficiency limit with manageable complexity.
• Both identified architectures exhibit high resilience to spectral variations, unlike traditional two-terminal designs.

Conclusions:

• The developed simulation environment enables performance prediction and optimization of complex integrated photovoltaic systems.
• Advanced multi-junction architectures with photon conversion offer a pathway to significantly enhance solar energy conversion efficiency.
• The proposed architectures provide superior spectral resilience compared to conventional multi-junction solar cells.