Organic Thin Films Based on DPP-DTT:C60 Blends Deposited by MAPLE

Area of Science:

• Organic electronics
• Materials science
• Photovoltaics

Background:

• Conjugated polymers and fullerenes are key materials for organic electronics.
• Developing efficient deposition techniques is crucial for fabricating organic photovoltaic devices.
• Poly[2,5-(2-octyldodecyl)-3,6-diketopyrrolopyrrole-alt-5,5-(2,5-di(thien-2-yl)thieno [3,2-b]thiophene)] (DPP-DTT) is a novel conjugated polymer for such applications.

Purpose of the Study:

• To investigate the feasibility of using Matrix-Assisted Pulsed Laser Evaporation (MAPLE) for depositing DPP-DTT:C60 blend thin films.
• To analyze the structural, morphological, optical, and electrical properties of these films.
• To understand the influence of material ratios and deposition parameters on film characteristics and device performance.

Main Methods:

• Thin films were deposited using MAPLE from frozen chloroform solutions of DPP-DTT:C60 blends.
• Various DPP-DTT:C60 weight ratios and laser pulse numbers were employed.
• Characterization included FTIR, UV-VIS, photoluminescence spectroscopy, and current-voltage measurements under illumination.

Main Results:

• MAPLE successfully preserved the chemical integrity of both DPP-DTT and C60, confirmed by FTIR.
• UV-VIS and photoluminescence spectra showed characteristic absorption and emission bands.
• Morphology featured aggregates and fibril-like structures.
• All deposited layers demonstrated photovoltaic cell behavior, irrespective of ratio and pulse number.

Conclusions:

• MAPLE is a viable technique for depositing complex conjugated polymer-based thin films for solar cell applications.
• The study highlights the potential of DPP-DTT:C60 blends for organic photovoltaics.
• Further optimization of MAPLE parameters could enhance device performance.