Imaging element and imaging apparatus
An imaging element according to an embodiment of the present disclosure includes: a first electrode including a plurality of electrodes; a second electrode opposed to the first electrode; a photoelectric conversion layer including an organic material provided between the first electrode and the second electrode; a first semiconductor layer provided between the first electrode and the photoelectric conversion layer, and including an n-type semiconductor material; and a second semiconductor layer provided between the second electrode and the photoelectric conversion layer, and including at least one of a carbon-containing compound having an electron affinity larger than a work function of the first electrode or an inorganic compound having a work function larger than the work function of the first electrode.
1. A light detecting element, comprising:
a first electrode;
a second electrode;
a photoelectric conversion layer between the first electrode and the second electrode;
a first semiconductor layer provided between the first electrode and the photoelectric conversion layer, and including an n-type semiconductor material; and
a second semiconductor layer provided between the second electrode and the photoelectric conversion layer, wherein the second semiconductor layer includes a carbon-containing compound having an electron affinity larger than a work function of the first electrode, and wherein the first electrode is a cathode and the second electrode is an anode.
2. The light detecting element according to claim 1 , wherein the first electrode includes an electric charge readout electrode and an electric charge accumulation electrode.
3. The light detecting element according to claim 1 , wherein a work function of the second electrode is smaller than a work function of the second semiconductor layer.
4. The light detecting element according to claim 2 , wherein a work function of the second semiconductor layer is larger than a work function of the electric charge accumulation electrode.
5. The light detecting element according to claim 1 , wherein light absorptance for visible light of the second semiconductor layer is 10% or less.
6. The light detecting element according to claim 1 , wherein
the first semiconductor layer includes an oxide semiconductor material, and
the oxide semiconductor material has, at a bottom of a conduction band, an energy level shallower than the work function of the first electrode.
7. The light detecting element according to claim 1 , further comprising a third semiconductor layer between the photoelectric conversion layer and the second semiconductor layer.
8. The light detecting element according to claim 7 , wherein the third semiconductor layer includes an organic compound or an inorganic compound having a band gap larger than a band gap of an organic material included in the photoelectric conversion layer.
9. The light detecting element according to claim 7 , wherein the third semiconductor layer has an energy level shallower than a HOMO of the second semiconductor layer, has an energy level shallower than a HOMO of the photoelectric conversion layer, and further has an energy level deeper than a work function of the second electrode.
10. The light detecting element according to claim 8 , wherein the organic compound has a glass transition point higher than 100° C.
11. The light detecting element according to claim 2 , further comprising an insulating layer between the first electrode and the first semiconductor layer, wherein
the electric charge readout electrode is electrically coupled to the first semiconductor layer via an opening provided in the insulating layer.
12. The light detecting element according to claim 2 , wherein a voltage is individually applied to each of the electric charge readout electrode and the electric charge accumulation electrode.
13. The light detecting element according to claim 1 , wherein one or a plurality of organic photoelectric converters that include the photoelectric conversion layer, and one or a plurality of inorganic photoelectric converters that performs photoelectric conversion in a wavelength region different from the organic photoelectric converters are stacked.
14. A light detecting apparatus provided with a plurality of pixels each including one or a plurality of light detecting elements, the light detecting elements each comprising:
a first electrode;
a second electrode;
a photoelectric conversion layer between the first electrode and the second electrode;
a first semiconductor layer provided between the first electrode and the photoelectric conversion layer, wherein the first semiconductor layer includes an n-type semiconductor material; and
a second semiconductor layer provided between the second electrode and the photoelectric conversion layer, and including a carbon-containing compound having an electron affinity larger than a work function of the first electrode, and wherein the first electrode is a cathode and the second electrode is an anode.
15. The light detecting apparatus according to claim 14 , wherein the first electrode is formed for each of the pixels.