Image pickup element, stacked image pickup element, and solid-state image pickup apparatus that exel in characteristics of transferring an electric charge accmlarted in photoelectric conversion layer
An image pickup element 10 includes a first electrode 21 , a charge accumulation electrode 24 that is arranged apart from the first electrode 21 , a photoelectric conversion unit 23 that contacts the first electrode 21 and is formed above the charge accumulation electrode 24 via an insulation layer 82 , and a second electrode 22 formed on the photoelectric conversion unit 23 . The photoelectric conversion unit 23 includes, from the second-electrode side, a photoelectric conversion layer 23 A, and an inorganic oxide semiconductor material layer 23 B including In a Ga b Sn c O d , and 0.30≤b/(a+b+c)≤0.50 and b≥c are satisfied.
1. An image pickup element, comprising:
a first electrode;
a charge accumulation electrode arranged apart from the first electrode;
a photoelectric conversion unit that contacts the first electrode and is formed above the charge accumulation electrode via an insulation layer; and
a second electrode formed on the photoelectric conversion unit, wherein
the photoelectric conversion unit includes, from a second-electrode side, a photoelectric conversion layer, and an inorganic oxide semiconductor material layer including a composite oxide of an indium oxide, a gallium oxide, and a tin oxide,
the composite oxide is In a Ga b Sn c O d ,
a indicates an atomic ratio of indium (In) atoms,
b indicates an atomic ratio of gallium (Ga) atoms,
c indicates an atomic ratio of tin (Sn) atoms, and
0.30≤b/(a+b+c)≤0.50 and b≥c are satisfied.
2. The image pickup element according to claim 1 , wherein 0.40≤b/(a+b+c)≤0.50 is satisfied.
3. The image pickup element according to claim 1 , wherein b≥1.2c is satisfied.
4. The image pickup element according to claim 1 , wherein
an energy average value of a maximum energy value in a conduction band of the inorganic oxide semiconductor material layer is E11,
an energy average value of a LUMO value of the photoelectric conversion layer is E12, and
E12≥E11 is satisfied.
5. The image pickup element according to claim 1 , wherein
an energy average value of a minimum energy value in a valence band of the inorganic oxide semiconductor material layer is E21,
an energy average value of a HOMO value of the photoelectric conversion layer is E22, and
E22≥E21 is satisfied.
6. The image pickup element according to claim 1 , wherein
an energy average value of a maximum energy value in a conduction band of the inorganic oxide semiconductor material layer is E11, and
E11≤−4.5 eV is satisfied.
7. The image pickup element according to claim 1 , wherein
the photoelectric conversion layer includes an n-type organic semiconductor.
8. The image pickup element according to claim 7 , wherein
the photoelectric conversion layer includes a fullerene or a fullerene derivative.
9. The image pickup element according to claim 1 , wherein
the photoelectric conversion layer includes an electron transport material.
10. The image pickup element according to claim 1 , wherein
the photoelectric conversion layer is configured to generate an electric charge, and
the electric charge is transferred to the first electrode via the inorganic oxide semiconductor material layer.
11. The image pickup element according to claim 10 , wherein
the electric charge is electrons.
12. A stacked image pickup element, comprising:
at least one of the image pickup element according to claim 1 .
13. A solid-state image pickup apparatus, comprising:
a plurality of the image pickup elements according to claim 1 .
14. A solid-state image pickup apparatus, comprising:
a plurality of the stacked image pickup elements according to claim 12 .