Solar cells will be fabricated by a single organic semiconductor

Mar 29, 2011 By Mikiko Tanifuji

The fabrication of organic thin-film solar cells has been simplified due to new research findings. Where previously two types of organic semiconductors were required, doping the semiconductor fullerene with molybdenum oxide renders the use of phthalocyanine unneccessary.

The Institute for Molecular Science, National Institute of Natural Sciences announced on March 3, 2011 that a research group led by Professor Masahiro Hiramoto has succeeded in converting conduction-type of from n- to p-type by molybdenum oxide (MoO3) doping. Details are published online in Applied Physics Letters on February 28, 2011.

Although organic thin-film solar cells are promising devices because of the advantages of being light weight, flexible and low cost, the conduction-type of organic semiconductors has not been controlled by doping as is done in silicon. Two species of organic semiconductors, n-type fullerene (C60) and p-type phthalocyanine (Pc), need to be used to form built-in fields in solar cells.

Researchers noticed that MoO3 is used to raise holes in organic electroluminescent materials. They have succeeded in converting conduction-type of C60 from n- to p-type by co-evaporation of MoO3 and C60. Energetic value of the Fermi level, 4.60eV, for nondoped C60 films measured by the Kelvin vibrating method was positively shifted to 5.88 eV by the co-evaporated doping of MoO3 at a concentration of 3300 ppm and approached the valence band of located at 6.4 eV. The upward bending of energy band in the Schottky junction formed at the interface between a metal (silver, Ag) and p-type C60 film formed by MoO3 doping was confirmed based on the photovoltaic properties. could be fabricated by a single material - fullerene C60.

Explore further: Making graphene in your kitchen

More information: Masayuki Kubo, et al. "Conduction-type control of fullerene films from n- to p-type by molybdenum oxide doping", Applied Physics Letters Vol.98, No. 7, p. 073311 (2011); doi:10.1063/1.3556312 (3 pages); published online 18 February 2011.

Provided by National Institute for Materials Science

5 /5 (1 vote)
add to favorites email to friend print save as pdf

Related Stories

Buckyballs Can Be Nontoxic... Maybe

Jan 09, 2006

Buckminsterfullerene, a form of carbon containing 60 atoms arranged like the facets of a soccer ball and one of the first and best studied nanoscale structures, has come under scrutiny in recent years over concerns ...

Sunny Record: Breakthrough for Hybrid Solar Cells

Feb 02, 2010

German scientists at the Department of Microsystems Engineering (IMTEK) and the Freiburg Materials Research Center (FMF) have succeeded in developing a method for treating the surface of nanoparticles which ...

Organic Molecules Stay on Top

Nov 19, 2007

The van der Waals force, a weak attractive force, is solely responsible for binding certain organic molecules to metallic surfaces. In a model for organic devices, it is this force alone that binds an organic film to a metallic ...

Recommended for you

Making graphene in your kitchen

17 hours ago

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.

Thinnest feasible nano-membrane produced

Apr 17, 2014

A new nano-membrane made out of the 'super material' graphene is extremely light and breathable. Not only can this open the door to a new generation of functional waterproof clothing, but also to ultra-rapid filtration. The ...

Wiring up carbon-based electronics

Apr 17, 2014

Carbon-based nanostructures such as nanotubes, graphene sheets, and nanoribbons are unique building blocks showing versatile nanomechanical and nanoelectronic properties. These materials which are ordered ...

Making 'bucky-balls' in spin-out's sights

Apr 16, 2014

(Phys.org) —A new Oxford spin-out firm is targeting the difficult challenge of manufacturing fullerenes, known as 'bucky-balls' because of their spherical shape, a type of carbon nanomaterial which, like ...

User comments : 0

More news stories

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.

NASA's MMS observatories stacked for testing

(Phys.org) —Engineers at NASA's Goddard Space Flight Center in Greenbelt, Md., accomplished another first. Using a large overhead crane, they mated two Magnetospheric Multiscale, or MMS, observatories – ...