Temperature Impact on Perovskite Solar Cells Under Operation

Area of Science:

• Photovoltaics
• Materials Science
• Renewable Energy

Background:

• Perovskite solar cells (PSCs) offer rapid efficiency gains, surpassing conventional silicon panels.
• Thermal stability remains a critical barrier to the commercialization of PSCs.
• Triple-cation PSCs with spiro-OMeTAD and PTAA hole extraction layers were investigated.

Purpose of the Study:

• To assess the impact of temperature on the photovoltaic performance of mesoporous triple-cation PSCs.
• To identify the mechanisms behind performance degradation under thermal stress.
• To compare the thermal stability of spiro-OMeTAD and PTAA as hole extraction materials.

Main Methods:

• In situ monitoring of photovoltaic performance under thermal stress (-5°C to 80°C).
• Analysis of perovskite crystal structure using X-ray diffraction.
• Investigation of hole extraction layer changes using electron scanning microscopy and X-ray photoelectron spectroscopy.

Main Results:

• Low temperatures (-5°C) showed minimal performance loss (<5%).
• Elevated temperatures (up to 80°C) caused significant decreases in open circuit potential and short circuit current.
• Perovskite crystal structure remained stable, but hole extraction layers degraded due to additive evaporation.
• PTAA-based PSCs exhibited lower irreversible performance loss (8.2±1.6%) compared to spiro-OMeTAD (21.6±2.3%) after thermal stress.

Conclusions:

• Temperature significantly impacts PSC performance, primarily by affecting the hole extraction layer.
• Additive evaporation from the hole extraction layer is the main cause of performance decline at higher temperatures.
• PTAA demonstrates superior long-term thermal stability over spiro-OMeTAD for mesoporous triple-cation PSCs.