Accurate performance characterization of perovskite-silicon tandem solar cells and modules

Peter Pasmans¹, Stefan Roest¹, Lukas Ziegler², Bernhard Mitchell²

¹Eternal Sun, The Hague, The Netherlands

² WAVELABS, Leipzig, Germany

E-mail: ppasmans@eternalsun.com

Abstract

Successful  commercialization  of perovskite-based  solar  modules  requires  ensuring  long-term reliability and establishing accurate and reproducible characterization methods to measure stable cell and module power. The inherent metastability and strong hysteresis of perovskites make accurate   and    stabilized    performance   measurements    challenging.    The    diverse   material compositions and device architectures further complicate the development of standardized testing methodologies.
  Characterizing perovskite-silicon tandem devices requires additional care. Sophisticated spectral control is needed to ensure accurate current matching critical for series-connected multi-junction devices,  otherwise  the  characteristics  of the  current-limiting  junction  will  dominate  the  test results. Double-sided illumination will be required to test the performance of two-terminal (2T) bifacial tandem devices. Also the differences in temperature coefficients between the perovskite and silicon layers has to be considered.
   Current industry  standards are moving towards  stabilization protocols that include maximum power point (MPP) tracking and asymptotic IV measurements. However, these protocols are time-consuming, often requiring minutes up to many hours, which makes them impractical for inline  characterization  during  manufacturing.  Furthermore,  accurately  determining  key  IV parameters  beyond  maximum  power  (Pmax),  alongside  accounting  for  pre-conditioning  and temperature effects, significantly complicates efficient inline module characterization.
   Given typical production line cycle times of 20-30 seconds, an effective inline quality control strategy requires a hybrid metrology approach, similar to existing thin-film module practices. This involves 100% inline IV testing within the available time to assess module power and to verify basic functionality or identify gross defects. This inline testing would be complemented by offline stabilization tests on a representative sample of modules to determine the stabilized power output (SPO). An accurate and reliable nameplate Pmax rating for the module is then derived by correlating its inline Pmax measurements with comprehensive offline SPO data.
   This  presentation  focuses  on  accelerating  the  performance   assessment  of  perovskite-based devices. Through close collaboration with leading industry partners and research experts, and by leveraging standardization efforts within the IEC and related communities, we aim to establish best-practice  recommendations  for  determining  PV  cell  and  module  power  output.  This presentation details our progress, integrating insights from a comprehensive literature review with experimental results. Our ultimate goal is to provide a consolidated framework for reliable and reproducible testing, thereby accelerating the commercialization of high-performance and reliable perovskite-based solar devices.