In-Operando Thermal Cycling of All-Perovskite Tandem Solar Cells

Abstract

In order to power spacecraft in low earth orbit (LEO), the assessment of performance and stability over a wider temperature range than that encountered terrestrially is required. To this end, state-of-the-art all-perovskite tandem solar cells, attractive for their high power to mass ratio and radiation tolerance, were subjected to temperature extremes from –100 to +100 °C while utilizing maximum power point tracking (MPPT) to assess the in-operando performance under simultaneous thermal cycling and AM0 illumination. These findings show that the wide band gap (WBG) subcell tuned to maximize power output with AM0 illumination undergoes severe phase segregation at temperatures above 50 °C, with only partial recovery within the 45-min dark cooling portion of the thermal cycling, resulting in greatly increased nonradiative recombination and current loss. Although carrier extraction is limited in the narrow band gap (NBG) mixed lead–tin perovskite subcell at low temperatures, this subcell is less prone to thermal instabilities under illumination, making it an attractive candidate for space power systems. Additionally, low-temperature photoluminescence (PL) and MPPT measurements are consistent with luminescence coupling between the WBG emission and NBG absorption, which is beneficial for increased power generation.