Organic semiconductor material and organic device using the same

Abstract

The present invention encompasses an organic field-effect transistor comprising an n-type organic semiconductor formed of a fullerene derivative having a fluorinated alkyl group which is expressed by the following chemical formula (wherein at least any one of R1, R2 and R3 is a perfluoro alkyl group or a partially-fluorinated semifluoro alkyl group each having a carbon number of 1 to 20), and a field-effect transistor production method comprising forming an organic semiconductor layer using the fullerene derivative by a solution process, and subjecting the organic semiconductor layer to a heat treatment in an atmosphere containing nitrogen or argon or in vacuum to provide enhanced characteristics to the organic semiconductor layer. The present invention makes it possible to form an organic semiconductor layer by a solution process and provide an organic field-effect transistor excellent in electron mobility and on-off ratio and capable of operating even in an ambient air atmosphere.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1( a) to 1(d) are sectional views showing typical examples of the arrangement of elements of a field-effect transistor.

FIG. 2 is a sectional view showing the configuration of a field-effect transistor in Inventive Example 3.

FIG. 3 is a graph showing the drain-current versus the drain-voltage before the heat treatment, as described herein in Inventive Example 3.

FIG. 4 is a graph showing the drain-current versus the drain-voltage after the heat treatment, as described herein in Inventive Example 3.

FIG. 5 is a graph showing the drain-current versus the drain-voltage after 24 hours from the introduction of ambient air, as described herein in Inventive Example 3.

Claims

1. A fullerene derivative having a fluorinated alkyl group, wherein the fullerene derivative has the following chemical formula:

2. An organic semiconductor device comprising an n-type organic semiconductor layer, comprising a fullerene derivative having a fluorinated alkyl group, wherein the fullerene derivative has the following chemical formula:

3. A field-effect transistor comprising an n-type organic semiconductor layer consisting of a fullerene derivative having a fluorinated alkyl group, wherein the fullerene derivative has the following chemical formula:

4. A method of producing a field-effect transistor comprising forming an organic semiconductor layer using a fullerene derivative having a fluorinated alkyl group, wherein the fullerene derivative has the following chemical formula:

5. A method of producing a field-effect transistor comprising forming an organic semiconductor layer using a fullerene derivative having a fluorinated alkyl group, wherein the fullerene derivative has the following chemical formula:

6. The method as defined in claim 4, wherein the organic semiconductor layer is heat-treated at a temperature of 50 to 200° C., and wherein said treatment is applied in an atmosphere containing nitrogen or argon or in vacuum.

7. The method as defined in claim 5, wherein the organic semiconductor layer is heat-treated at a temperature of 50 to 200° C., and wherein said treatment is applied in an atmosphere containing nitrogen or argon or in vacuum.