Simulation and analysis of III-V heterostructure solar cells for a continuous HVPE process

A continuous hydride vapor phase epitaxy (HVPE) growth system has the potential to realize large-scale production of low-cost III-V solar cells. To aid the process development, this work integrates HVPE reactor model with III-V solar cell simulation to intimately tie the device performance to the process design and operation. This modeling approach sets a potential to connect the control of a growth system directly to the device performance without intervening ancillary models. The approach of direct process-to-device level simulation is demonstrated through simulating the continuous HVPE fabrication of a model solar cell structure as a function of critical process parameter. Critical reactor design features as well as sensitive material parameters in affecting device performance are discussed. An illustrative case study is carried out to investigate the influence of gas curtain velocity on the solar cell efficiency using the integration of reactor and solar cell models. Through the correlations determined by the process-to-device simulations, the sensitivity of critical reactor variables in affecting cell efficiency can be established and optimized through the impact on solar cell performance directly. This integrated device performance-reactor design approach allows for the design of the process and its real-time control with direct knowledge of the expected dependence of device performance on reactor design trade-offs.