Photoelectric conversion element

1. A photoelectric conversion element comprising:

a conductive film;

an electron transport layer overlying the conductive film,

the electron transport layer including at least one of titanium oxide and zinc oxide;

a photoelectric conversion layer overlying the electron transport layer, the photoelectric conversion layer including:

a first material represented by the following formula (1′):

wherein R 1 represents a hydrogen atom or a straight-chain or branched-chain alkyl group having 2 to 6 carbon atoms; each of R 2 and R 3 independently represents one of an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, and a decyl group; each of R 4 and R 5 independently represents a straight-chain or branched-chain alkyl group having 6 to 12 carbon atoms; and n represents an integer of 2 or 3; and

a second material represented by the following formula (2);

wherein each of Y 1 and Y 2 independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or an aralkyl group, but each of Y 1 and Y 2 does not represent a hydrogen atom at the same time: Ar represents an aryl group; and a structural unit represented by the following formula (F) is a fullerene skeleton having 60 carbon atoms:

a hole transport layer overlying the photoelectric conversion layer; and

an electrode.

2. The photoelectric conversion element of claim 1 , wherein the second material is represented by the following formula (3):

wherein Z represents phenyl group, 1-naphthyl group, 2-naphthyl group, or n-hexyl group.

3. The photoelectric conversion element of claim 1 , wherein a weight ratio of the first material to the second material is in the range of from 35/65 to 80/20.

4. The photoelectric conversion element of claim 1 , wherein the electron transport layer includes a polymer compound having at least one of a secondary alkylamino group, a tertiary alkylamino group, and a quaternary ammonium salt group.

5. The photoelectric conversion element of claim 1 , further comprising a layer overlying the electron transport layer, the layer including a low-molecular-weight amine compound represented by the following formula (4):

wherein each of R 6 and R 7 independently represents an alkyl group having 1 to 4 carbon atoms or benzyl group, while R 6 and R 7 may share bond connectivity to form a ring; Y represents a divalent aromatic group having 6 to 14 carbon atoms or an alkylene group having 1 to 4 carbon atoms; and A represents one of the following substituents

—COOH

—P(═O)(OH) 2

—Si(OH) 3 .

6. The photoelectric conversion element of claim 1 , wherein the first material includes at least one of the following Compounds 9, 12, or 14: