High voltage vacuum-processed perovskite solar cells with organic semiconducting interlayers

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Efficient charge transport and collection are crucial for perovskite solar cells (PSCs) to minimize recombination losses.
• Vacuum processing enables sequential layer deposition, facilitating the exploration of material combinations for optoelectronic devices.

Purpose of the Study:

• To investigate the impact of interlayers and electrode work function modification on fully vacuum-deposited PSC performance.
• To compare the efficacy of common electron buffer layers (BCP) and organic light-emitting diode (OLED) injection materials (Liq) as interlayers.

Main Methods:

• Fabrication of perovskite solar cells using sequential vacuum deposition techniques.
• Evaluation of different electron buffer layers, including bathocuproine (BCP) and lithium quinolate (Liq), individually and in combination.
• Assessment of device performance, photovoltage, stability, and efficiency under continuous operation.

Main Results:

• Introducing BCP and BCP/Liq interlayers significantly enhanced photovoltage and operational stability in vacuum-deposited PSCs.
• Solar cells utilizing these interlayers achieved efficiencies of approximately 19%, a notable result for methylammonium lead iodide absorbers.
• Low work function metal electrodes yielded high voltage but compromised device stability.

Conclusions:

• The strategic use of BCP and BCP/Liq interlayers is effective in improving the performance and stability of vacuum-processed PSCs.
• Vacuum-deposited interlayers offer a viable route to optimize charge transport and collection in perovskite solar cells.
• Achieving high efficiency and stability in PSCs is attainable through careful selection and combination of transport layers and electrodes.