The most stable perovskite photovoltaic modules to date employ an architecture of Glass/FTO/TiO2/porous-oxide/carbon black structure where the perovskite ink is impregnated through the top two porous layers. Researchers at NREL have improved on this concept by effectively inverting this structure by placing the carbon black electrode onto the glass substrate at the bottom, followed by the perovskite and electron transport layers, then encapsulating with a transparent conductive oxide (TCO) layer on top. In this design, the perovskite film does not have to crystallize through small pores - a step in the traditional process which typically constrains proper perovskite film crystallization and resulting power conversion performance. Adding to this new benefit, this structure can be illuminated through the top of the device rather than through the glass substrate. Finally, while this architecture provides outstanding durability without encapsulation, the top TCO layer on the surface provides extra reinforcement and therefore extra stability to the device.
This technology is within the Perovskite Device Architecture and Perovskite Film Stability groups of NREL’s perovskite portfolio. For further information regarding NREL's broader perovskite portfolio, please visit NREL's Perovskite Patent Portfolio website here or contact Bill Hadley at: