New PCBM/carbon based electron transport layer for perovskite solar cells

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Carbon is abundant, inexpensive, and explored as a component in perovskite solar cells.
• Carbon has been utilized as a hole transport layer or counter electrode.
• Perovskite solar cells require efficient charge transport layers to optimize performance.

Purpose of the Study:

• To investigate carbon's potential as a charge transport layer in perovskite solar cells when combined with PCBM.
• To enhance the energy conversion efficiency of methylammonium lead iodide chloride (CH3NH3PbI3-xClx) solar cells.
• To explore cost-effective materials for reducing solar cell manufacturing costs.

Main Methods:

• Deposition of an ultra-flat carbon layer using electron beam (e-beam) irradiation.
• Fabrication of perovskite solar cells utilizing PCBM/carbon and PCBM/C60 charge transport layers.
• Quantitative analysis of interfacial charge dynamics, including quenching efficiency, defect passivation, and electrical resistances.

Main Results:

• The e-beam deposited ultra-flat carbon layer demonstrated superior conductivity compared to PCBM/C60.
• PCBM/carbon exhibited comparable charge quenching efficiency to PCBM/C60.
• Improved interface defect passivation and enhanced series and shunt resistances were observed with PCBM/carbon.

Conclusions:

• Carbon, when combined with PCBM, serves as an effective charge transport layer in perovskite solar cells.
• The PCBM/carbon layer led to a power conversion efficiency (PCE) of 16%, an increase from the 14% PCE of the PCBM/C60 reference.
• Cost-effective carbon materials show significant potential for reducing the production costs of high-efficiency perovskite solar cells.