Performance Constraints of All-Perovskite Tandem Solar Cells in Low-Intensity, Low-Temperature Environments.

Area of Science:

• Materials Science
• Renewable Energy
• Space Technology

Background:

• All-perovskite tandem solar cells (2J-PSCs) offer high power-to-weight ratios, making them attractive for space applications.
• Deep space missions require solar cells to operate under low-intensity, low-temperature (LILT) conditions.

Purpose of the Study:

• To evaluate the performance and identify limitations of 2J-PSCs under LILT conditions relevant to deep space environments.
• To compare the LILT performance of 2J-PSCs with single-junction perovskite solar cells (1J-PSCs).

Main Methods:

• Performed temperature-dependent current density-voltage (J-V) measurements under varying solar intensities (AM0, 0.1 AM0, 0.01 AM0).
• Analyzed the composition and stability of perovskite layers at low temperatures.

Main Results:

• 2J-PSCs (1.80 eV/1.27 eV) showed significant efficiency losses and operational issues (S-shapes) at temperatures below 250 K and low light.
• Single-junction PSCs (1.54 eV) demonstrated stable or improved efficiency under LILT conditions.
• Perovskite demixing in the 1.80 eV top cell, caused by a high Br ratio, was identified as the primary cause of performance degradation in 2J-PSCs at low temperatures.

Conclusions:

• The demixing of the wide-bandgap perovskite in 2J-PSCs under LILT conditions leads to ion-induced losses and current mismatch, hindering their suitability for deep space missions.
• The observed performance issues in 2J-PSCs are reversible upon heating, indicating a temperature-dependent degradation mechanism.
• 1J-PSCs are more resilient for LILT applications, while 2J-PSC technology requires further development to overcome low-temperature stability challenges.