A solution-processed bathocuproine cathode interfacial layer for high-performance bromine-iodine perovskite solar...

Area of Science:

• Materials Science
• Renewable Energy

Background:

• Perovskite films often exhibit rough surfaces due to voids between grain domains, hindering efficient charge transfer in solar cells.
• A smooth interface between the perovskite layer and the top electrode is crucial for optimizing planar perovskite solar cell performance.

Purpose of the Study:

• To improve the efficiency and performance of bromine-iodine based perovskite solar cells.
• To investigate the effect of a solution-processed bathocuproine (sBCP) interfacial layer on the cathode interface.
• To compare the performance of sBCP with vacuum-evaporated bathocuproine (eBCP).

Main Methods:

• Incorporation of a solution-processed bathocuproine (sBCP) interfacial layer at the cathode side of perovskite solar cells.
• Characterization of surface morphology and charge transfer resistance.
• Fabrication and performance testing of CH3NH3PbI3-xBrx based perovskite solar cells.

Main Results:

• The sBCP layer effectively flattened the cathode interface, reducing charge transfer resistance compared to eBCP.
• Perovskite solar cells with sBCP achieved a high fill factor exceeding 85%.
• Power conversion efficiencies exceeding 13% were recorded for the CH3NH3PbI3-xBrx based perovskite solar cells.

Conclusions:

• Solution-processed BCP is an effective interfacial layer for improving perovskite film morphology and cathode contact.
• The enhanced fill factor and efficiency are attributed to the improved film coverage and smoother surface provided by sBCP.
• This approach offers a promising strategy for developing high-performance planar perovskite solar cells.