Project Titlep-Type Semiconductor Nickel Oxide As An Anodal Interfacial Layer In Organic Photovoltaics
Track Code2007-112
Short Description

A novel composition organic photovoltaic cell that uses a nickel oxide layer to improve stability and performance over traditional formulations.

#materials #photovoltaic #semiconductor #component #energy #solar


Northwestern researchers developed organic photovoltaic (OPV) cells that offer a potential alternative to conventional Si solar cells. The OPVs developed use the typical poly(3-hexylthiophene) (P3HT) and fullerene derivative [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) active layer but replace the typical electron blocking layer (EBL)/hole-transporting layer (HTL) Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) with the novel composition nickel oxide. Nickel oxide (NiO), a cubic wide band-gap semiconductor, which is essentially transparent as very thin layers, is a p-type to facilitate hole conduction (HTL). This novel composition is designed to enhance OPV performance by reducing loss of open-circuit voltage that is common with other cells. NiO has a band structure well-suited for P3HT:PCBM OPVs and provides an ohmic contact to P3HT while having a sufficiently high conduction band minimum to function as an EBL. The device structure of glass/ITO/NiO/P3HT:PCBM/LiF/Al reported here proved an effective PEDOT:PSS replacement affording both exceptional fill factor (69%) and open-circuit voltage (638 mV) metrics, as well as a BHJ cell power conversion efficiency of 5.2%, versus a glass/ITO/P3HT:PCBM/LiF/Al control device (51%, 0.515mv, 2.9% respectively). Replacement of PEDOT:PSS with a p-type oxide semiconductor anode interfacial layer in an archetypical BHJ photovoltaic device results in a dramatic performance increase, while exhibiting excellent device stability. The value of such hole-transporting/electron-blocking interfacial layers is clearly demonstrated and should be applicable to other organic photovoltaics.

TagsENERGY: solar, MATERIALS: photovoltaic, MATERIALS: semiconductor
Posted DateMay 15, 2014 2:30 PM


Bruce Buchholz

Robert P.H. Chang*

Michael D Irwin

Tobin J Marks*


For use in organic photovoltaic devices


• Reduced interfacial power losses in BHJ photovoltaics
• Enhanced OPV device stability
• Eliminate use of PEDOT:PSS in OPVs
• Low cost
• Lightweight with mechanical flexibility

• Suitable to high-throughput, low-cost reel-to-reel coating processes


IP Status

A patent application has been filed.

Contact Information

Zach Brown, PhD
Invention Associate

(p) (847) 491-4629