Designing Modules to Prevent Reverse Bias Degradation in Perovskite Solar Cells when Partial Shading Occurs

When a solar cell in a panel is shaded, the illuminated cells can place a large reverse bias on the shaded cell to attempt to force current through it. Although the panel can continue to produce power, the reverse bias can cause significant problems for the shaded cell. In the case of perovskite solar modules, Joule heating and irreversible electrochemical reactions will degrade the cell. Some photovoltaic technologies use bypass diodes to solve this problem. To prevent both a perovskite cell and an all-perovskite tandem cell from falling into reverse bias breakdown while shaded, no more than two cells per bypass diode are allowed, which is likely to be prohibitively expensive for many applications. Herein, how many solar cells can be protected by one bypass diode in single-junction and multijunction perovskite modules is explored. It is easier to incorporate bypass diodes into modules with singulated cells than with monolithic panels. It is shown that perovskite-silicon tandems can be protected with fewer bypass diodes than with single-junction perovskite modules. It is suggested that if bypass diodes cannot be feasibly incorporated, then the panels should be deployed in utility-scale power plants.

Automated summary

When a solar cell is shaded in a panel, it can cause significant problems due to reverse bias, with some technologies using bypass diodes to address this issue. The number of solar cells that can be protected by one bypass diode needs to be explored, with singulated cell modules being easier to incorporate bypass diodes than monolithic panels. Perovskite-silicon tandems can be protected with fewer bypass diodes than single-junction perovskite modules, but if bypass diodes cannot be feasibly incorporated, deployment in utility-scale power plants is suggested.