Semitransparent polymer solar cells with 5% power conversion efficiency using photonic crystal reflector

Area of Science:

• Materials Science
• Renewable Energy
• Optoelectronics

Background:

• Semitransparent polymer solar cells (ST-PSCs) offer potential for diverse applications but require efficiency enhancements.
• Light management is crucial for maximizing light absorption and minimizing optical losses in solar cells.

Purpose of the Study:

• To enhance the efficiency of ST-PSCs.
• To investigate the use of one-dimensional photonic crystals (1DPCs) as high reflectors in ST-PSCs.
• To optimize 1DPCs for improved light management within the active layer.

Main Methods:

• Fabrication of ST-PSCs incorporating 1DPCs.
• 1DPCs composed of alternating layers of WO3 (65.8 nm) and LiF (95.5 nm).
• Matching the photonic band gap of 1DPCs with the absorption spectrum of the active layer.

Main Results:

• ST-PSCs with 8 pairs of 1DPC demonstrated improved performance.
• Short-circuit current density (Jsc) increased from 8.12 mA/cm² to 9.76 mA/cm² (20.2% enhancement).
• Power conversion efficiency (PCE) rose from 4.24% to 5.16% (~21.7% increase).

Conclusions:

• 1DPCs effectively enhance light reflection within ST-PSCs.
• Optimized 1DPCs significantly boost Jsc and PCE.
• This approach offers a promising route to highly efficient ST-PSCs for practical applications.