Organic photodiode provided with an active zone comprising means for promoting charge carrier collection and conduction
View Patent ↗A photodiode including at least one active zone located between a first electrode and a second electrode, the active zone including elongated conducting or semiconducting elements extending between the electrodes and configured to promote collection and transport of charge carriers in the active zone.
1. A diode comprising:
an active zone located between a first electrode and a second electrode, the active zone being formed from at least one semiconducting material, the active zone further comprising one or more conducting or semiconducting elements formed from elongated conducting zones that extend between the electrodes in the material of the active zone along a direction forming a non-zero angle with the electrodes, the elements not being connected to the electrodes and among the elements, one or more first elements is based on a first material promoting conduction of holes, and one or more second elements is based on a second material promoting conduction of electrons,
the first material and the second material being based on a material different from the material in the active zone in which the first elements and the second elements are in contact, the first material having a hole conductivity higher than a hole conductivity of the material in the active zone, and the second material promoting conduction of electrons having a conductivity higher than an electron conductivity of the material in the active zone.
2. The diode according to claim 1 , the active zone being formed from at least one semiconducting polymer material.
3. The diode according to claim 2 , the elements being based on a material with better conductivity than the semiconducting material in the active zone.
4. The diode according to claim 1 , wherein the elements are based on a material in which mobility of charge carriers is at least twice as high as mobility of charge carriers in the at least one semiconducting material in the active zone.
5. The diode according to claim 1 , wherein at least one of the elements is based on a conducting polymer material.
6. The diode according to claim 1 , wherein at least one of the elements is based on an ambipolar material.
7. The diode according to claim 1 , wherein the elements include:
at least one element based on a P type conducting material, chosen from among: Au, ITO, Cu, Ni, Ag, Pd, PDOT:PSS,
at least one second element based on an N type conducting material, chosen from among: Ca, Al.
8. The diode according to claim 1 , wherein at least one of the elements is based on a metal covered with a layer capable of modifying work function of the metal.
9. The diode according to claim 8 , wherein the conducting or semiconducting elements further include:
at least one first element based on a metal covered by a P type SAM layer based on PFBT or pentafluorobenzenethiol,
or
at least one first element based on a metal covered by an N type SAM layer based on 4MTP or methoxythiolphenol,
or
at least one or plural first element based on a metal covered by an N type SAM layer based on 4MTP or methoxythiolphenol and at least one first element based on a metal covered by a P type SAM layer based on PFBT or pentafluorobenzenethiol.
10. The diode according to claim 8 , in which the active zone is formed from a first region based on the first polymer material and a second region adjacent to the first region and based on the second polymer material, at least one of the elements being based on a metal zone passing through the first region and the second region, the metal zone being covered in the first region by a layer capable of increasing output work of the metal, the metal zone being also covered in the second region with a layer capable of reducing the output work of the metal.
11. The diode according to claim 1 , wherein the active zone is formed from a mix of a first polymer material and a second polymer material.
12. The diode according to claim 1 , wherein the active zone is formed from a mix of PCBM and P3HT.
13. The diode according to claim 1 , in which elements are formed from a set of tracks, an arrangement of the elements in the active zone forming an alternation of tracks promoting conduction of holes and of tracks promoting conduction of electrons.
14. The diode according to claim 13 , wherein tracks promoting conduction of electrons and tracks promoting conduction of holes are arranged in a form of interdigitated combs.
15. The diode according to claim 14 , wherein the first electrode acts as an anode and the second electrode acts as a cathode, elements promoting conduction of holes being arranged closer to the cathode than to the anode, elements promoting conduction of electrons being arranged closer to the anode than to the cathode.
16. The diode according to claim 15 , wherein elements promoting conduction of holes are arranged at a distance d1 from the cathode at a distance Δ1 from the anode, and wherein d1/Δ1≦10, elements promoting conduction of electrons being arranged at a distance not more than d2 from the anode and at least Δ2 from the cathode, in which d2/Δ2≦10.
17. The diode according to claim 1 , wherein the conducting or semiconducting elements have a total surface area that can be exposed to light radiation at least 10 times smaller than a surface area of the active zone exposed to the light radiation.
18. The diode according to claim 1 , wherein the conducting or semiconducting elements have a thickness less than 100 nanometers.
19. A microelectronic device comprising at least one diode according to claim 1 , the conducting elements being connected to a load in a form of an accumulator or a capacitor.