[Organic solar cell based on alkylthiol/Au self-assembly film as buffer layer]

Area of Science:

• Organic electronics
• Materials science
• Photovoltaics

Context:

• Interface engineering is crucial for organic solar cell (OSC) efficiency.
• Traditional Poly(3,4-ethylenedioxythiophene) : poly(styrene sulfonate) (PEDOT:PSS) layers can lead to exciton quenching.
• Optimizing the organic/inorganic interface is key to device improvement.

Purpose:

• To investigate the effect of alkylthiol self-assembled layers on gold electrodes as a buffer layer in OSCs.
• To replace the conventional PEDOT:PSS layer with a tunable alkylthiol/Au interface.
• To study the influence of varying alkyl chain lengths on device performance.

Summary:

• Alkylthiol (ethanethiol, hexanethiol, dodecanethiol) layers were introduced between the inorganic electrode and the organic active layer (P3HT:PCBM) in an OSC.
• The self-assembled monolayers on a thin gold film prevented direct contact between gold nanoparticles and the active layer, thus reducing exciton quenching.
• Device performance, particularly the short-circuit current, improved with increasing alkyl chain length, with dodecanethiol showing the best results.

Impact:

• The alkylthiol/Au interface modification improved the short-circuit current from 5.19 mA/cm² to 6.24 mA/cm² in OSCs utilizing dodecanethiol.
• This strategy offers a method to enhance OSC performance by controlling interfacial properties.
• The findings suggest potential for further optimization of organic solar cells through interface engineering.