Low-temperature, solution-processed MoO(x) for efficient and stable organic solar cells.

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Hole extraction layers are crucial for efficient organic solar cell (OSC) performance.
• Molybdenum oxide (MoO(x)) is a common material, but traditional deposition methods can be energy-intensive or lead to stability issues.
• PEDOT:PSS, while widely used, suffers from poor long-term stability in OSCs.

Purpose of the Study:

• To develop a novel, solution-processed molybdenum oxide (MoO(x)) hole-extraction layer for organic solar cells.
• To investigate the performance and stability of these sol-gel processed MoO(x) (sMoO(x)) layers in P3HT:PC(60)BM OSCs.
• To compare the sMoO(x) layers with thermally evaporated MoO(3) (eMoO(3)) and PEDOT:PSS based devices.

Main Methods:

• Sol-gel processing using a Bis(2,4-pentanedionato)molybdenum(VI)dioxide/isopropanol solution.
• Moderate thermal post-deposition treatment at 150 °C in a nitrogen (N2) ambient.
• Fabrication and characterization of P3HT:PC(60)BM organic solar cells (OSCs) incorporating the sMoO(x) layers.
• Performance and stability testing of the fabricated OSCs.

Main Results:

• Achieved sol-gel processed MoO(x) (sMoO(x)) layers with a high work-function of 5.3 eV.
• Demonstrated sMoO(x) layers in P3HT:PC(60)BM OSCs yielding a high filling factor of approximately 65% and an efficiency of 3.3%.
• Observed significantly improved device stability for OSCs using sMoO(x) compared to those with PEDOT:PSS.

Conclusions:

• Sol-gel processed MoO(x) provides an effective and stable hole-extraction layer for organic solar cells.
• The moderate processing conditions and high performance make sMoO(x) a promising alternative to conventional hole-extraction materials.
• This approach enhances both the efficiency and operational lifetime of organic solar cells.