Dibenzo[f,h]thieno[3,4-b] quinoxaline-based small molecules for efficient bulk-heterojunction solar cells

Area of Science:

• Organic electronics
• Materials science
• Photovoltaics

Background:

• Dibenzo[f,h]thieno[3,4-b]quinoxaline derivatives are promising organic semiconductors.
• Organic solar cells require efficient light-harvesting materials.

Purpose of the Study:

• To synthesize and characterize two isomeric dibenzo[f,h]thieno[3,4-b]quinoxaline-based compounds.
• To evaluate their performance as sensitizers in solution-processed bulk heterojunction solar cells.

Main Methods:

• Synthesis of isomeric compounds 1 and 2 with a dibenzo[f,h]thieno[3,4-b]quinoxaline core and peripheral arylamines.
• Fabrication and testing of bulk heterojunction solar cells using these compounds and PCBM.
• Analysis of device performance, including power conversion efficiency and external quantum yield.

Main Results:

• Compound 1, when blended with PCBM (67 wt %), yielded a power conversion efficiency of 1.70%.
• An external quantum yield of 55% was achieved for the cell fabricated with compound 1.
• The resulting films exhibited balanced electron and hole mobility and favorable morphology.

Conclusions:

• The synthesized dibenzo[f,h]thieno[3,4-b]quinoxaline derivatives show promise for organic solar cell applications.
• Optimized device fabrication can lead to efficient power conversion and high external quantum yields.
• Balanced charge transport and good film morphology are critical for high-performance organic solar cells.