Photovoltaic devices with an active layer from a stamping transfer technique: single layer versus double layer

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Organic photovoltaic (OPV) devices offer a promising alternative to traditional silicon solar cells due to their flexibility and low-cost manufacturing potential.
• Achieving high power conversion efficiency (PCE) in OPVs is crucial for their commercial viability.
• Controlling the morphology and interface of the active layer is key to optimizing charge generation and transport.

Purpose of the Study:

• To investigate the fabrication of organic photovoltaic devices using a stamping transfer technique.
• To compare the performance of single-layered versus double-layered active films prepared via this method.
• To understand the impact of active layer morphology on device efficiency.

Main Methods:

• Fabrication of single and double-layered active films (P3HT/PCBM) using a stamping transfer technique with ultraviolet curable polycarbonate films.
• Optimization of the P3HT/PCBM ratio in double-layered devices.
• Characterization of the active layer interface using Auger electron spectroscopy.
• Performance evaluation of the fabricated organic photovoltaic devices.

Main Results:

• Successful fabrication of single-layered and ratio-controlled double-layered P3HT/PCBM active films via stamping transfer.
• Achieved maximum PCE of 2.85% for single-layered and 3.24% for optimized double-layered devices.
• Observed formation of an intermixed zone with a concentration gradient at the interface of the transferred double layers during thermal annealing, confirmed by Auger electron spectroscopy.

Conclusions:

• The stamping transfer technique is effective for fabricating OPV active layers with controlled morphology.
• The intermixed zone formed in double-layered devices enhances carrier transport and charge generation, leading to improved PCE.
• This study demonstrates a viable method for optimizing OPV performance through controlled interface engineering.