Photoelectric conversion element and method for producing the same
A photoelectric conversion element capable of reducing a specific dark current. In a photoelectric conversion element ( 10 ) including an anode ( 12 ), a cathode ( 16 ), and an active layer ( 14 ) provided between the anode and the cathode, the active layer contains a p-type semiconductor material having a band gap of 0.5 eV to 1.58 eV, and an n-type semiconductor material, the n-type semiconductor material is a C 60 fullerene derivative, and on an image obtained by binarizing an image of the active layer observed by a transmission electron microscope, the junction length between a phase of the n-type semiconductor material and a phase of the p-type semiconductor material is 120 μm to 170 μm per square micrometer of the area of the binarized image.
1. A photodetector, comprising:
an anode;
a cathode; and
an active layer provided between the anode and the cathode, wherein
the active layer contains a p-type semiconductor material having a band gap of 0.5 eV to 1.58 eV, and an n-type semiconductor material,
the n-type semiconductor material is a C 60 fullerene derivative, and
on an image obtained by binarizing an image of the active layer observed by a transmission electron microscope, a junction length between a phase of the n-type semiconductor material and a phase of the p-type semiconductor material is 120 μm to 170 μm per square micrometer of area of the binarized image, wherein the photodetector provides a ratio between a dark current at −5V applied between the anode and the cathode and a dark current at −2V applied between the anode and the cathode in a range from 1.7 to 8.2.
2. The photodetector according to claim 1 , wherein the p-type semiconductor material is a polymer compound having a constitutional unit containing a thiophene skeleton.
3. The photodetector according to claim 1 , wherein the C 60 fullerene derivative is C60PCBM.
4. An image sensor comprising the photodetector according to claim 1 .
5. A fingerprint authentication device comprising the photodetector according to claim 1 .
6. The photodetector according to claim 1 , the bandgap of the p-type semiconductor material is 1.18 eV to 1.58 eV.
7. A method for producing a photodetector, comprising an anode, a cathode, and an active layer provided between the anode and the cathode, comprising:
forming the active layer comprising a step (i) of applying an ink containing an n-type semiconductor material, a p-type semiconductor material having a band gap of 0.5 eV to 1.58 eV, and a solvent to a subject to be applied, to obtain a coating film, and a step (ii) of removing the solvent from the coating film, wherein
the n-type semiconductor material is a C 60 fullerene derivative, and
on an image obtained by binarizing an image of the active layer observed by a transmission electron microscope, a junction length between the n-type semiconductor material and the p-type semiconductor material is 120 μm to 170 μm per square micrometer of area of the binarized image, wherein the produced photodetector provides a ratio between a dark current at −5V applied between the anode and the cathode and a dark current at −2V applied between the anode and the cathode in a range from 1.7 to 8.2.
8. The method for producing a photodetector according to claim 6 , wherein the bandgap of the p-type semiconductor material is a 1.18 eV to eV 1.58.
9. The method for producing a photodetector according to claim 6 , wherein the p-type semiconductor material is a polymer compound having a constitutional unit containing a thiophene skeleton.
10. The method for producing a photodetector according to claim 6 , wherein the C 60 fullerene derivative is C60PCBM.