Organic photodetector and electronic device having the same
An organic photodetector includes: an anode; a cathode facing the anode; and an active layer disposed between the anode and the cathode and including a first layer and a second layer. The first layer is disposed between the anode and the second layer, the first layer includes a p-type organic semiconductor and an n-type organic semiconductor, and the second layer includes the p-type organic semiconductor.
1 . An organic photodetector comprising:
an anode;
a cathode facing the anode;
an active layer disposed between the anode and the cathode, the active layer comprising a first layer and a second layer;
a hole transport region disposed between the anode and the active layer; and
the hole transport region comprises a hole transport layer,
wherein:
the first layer is disposed between the anode and the second layer,
the first layer comprises a p-type organic semiconductor and an n-type organic semiconductor, and
the second layer consists only of the p-type organic semiconductor.
2 . The organic photodetector of claim 1 , wherein the n-type organic semiconductor has a lowest unoccupied molecular orbital (LUMO) energy level lower than that of the p-type organic semiconductor.
3 . The organic photodetector of claim 1 , wherein a lowest unoccupied molecular orbital (LUMO) energy level of the p-type organic semiconductor is in a range of about −4.0 electron volts (eV) to about −2.9 eV, and a LUMO energy level of the n-type organic semiconductor is in a range of about −4.5 eV to about −3.5 eV.
4 . The organic photodetector of claim 1 , wherein the p-type organic semiconductor consists of boron subphthalocyanine chloride (SubPc), copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), or any combination thereof.
5 . The organic photodetector of claim 1 , wherein the n-type organic semiconductor comprises C60 fullerene, C70 fullerene, or any combination thereof.
6 . The organic photodetector of claim 1 , wherein the first layer comprises a mixed layer of the p-type organic semiconductor and the n-type organic semiconductor.
7 . The organic photodetector of claim 1 , wherein:
the first layer comprises a bilayer comprising a first donor layer and a first acceptor layer,
the first acceptor layer is disposed between the first donor layer and the second layer,
the first donor layer comprises the p-type organic semiconductor, and
the first acceptor layer comprises the n-type organic semiconductor.
8 . The organic photodetector of claim 7 , wherein:
the first donor layer and the first acceptor layer form a PN junction, and
the first acceptor layer and the second layer form a PN junction.
9 . The organic photodetector of claim 7 , wherein the p-type organic semiconductor comprised in the first donor layer is substantially identical to the p-type organic semiconductor comprised in the second layer.
10 . The organic photodetector of claim 9 , wherein the p-type organic semiconductor comprises SubPc, CuPc, DBP, or any combination thereof.
11 . The organic photodetector of claim 7 , wherein:
a thickness of the first donor layer is in a range of about 10 Angstroms (Å) to about 1,000 Å,
a thickness of the first acceptor layer is in a range of about 10 Å to about 1,000 Å, and
a thickness of the second layer is in a range of about 5 Å to about 200 Å.
12 . The organic photodetector of claim 1 , further comprising:
an electron transport region disposed between the active layer and the cathode, wherein:
the electron transport region comprises a buffer layer, a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.
13 . The organic photodetector of claim 12 , wherein:
the hole transport layer comprises a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof:
wherein, in Formulae 201 and 202,
L 201 to L 204 may each independently be a C 3 -C 60 carbocyclic group unsubstituted or substituted with at least one R 10a or a C 1 -C 60 heterocyclic group unsubstituted or substituted with at least one R 10a ,
L 205 may be *—O—*′, *—S—*′, *—N(Q 201 )-*′, a C 1 -C 20 alkylene group unsubstituted or substituted with at least one R 10a , a C 2 -C 20 alkenylene group unsubstituted or substituted with at least one R 10a , a C 3 -C 60 carbocyclic group unsubstituted or substituted with at least one R 10a , or a C 1 -C 60 heterocyclic group unsubstituted or substituted with at least one R 10a ,
xa1 to xa4 may each independently be an integer from 0 to 5,
xa5 may be an integer from 1 to 10,
R 201 to R 204 and Q 201 may each independently be a C 3 -C 60 carbocyclic group unsubstituted or substituted with at least one R 10a or a C 1 -C 60 heterocyclic group unsubstituted or substituted with at least one R 10a ,
R 201 and R 202 may optionally be bound to each other via a single bond, a C 1 -C 5 alkylene group unsubstituted or substituted with at least one R 10a , or a C 2 -C 5 alkenylene group unsubstituted or substituted with at least one R 10a to form a C 8 -C 60 polycyclic group unsubstituted or substituted with at least one R 10a ,
R 203 and R 204 may optionally be bound to each other via a single bond, a C 1 -C 5 alkylene group unsubstituted or substituted with at least one R 10a or a C 2 -C 5 alkenylene group unsubstituted or substituted with at least one R 10a to form a C 8 -C 60 polycyclic group unsubstituted or substituted with at least one R 10a , and
na1 may be an integer from 1 to 4,
R 10a is:
deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group;
a C 1 -C 60 alkyl group, a C 2 -C 60 alkenyl group, a C 2 -C 60 alkynyl group, or a C 1 -C 60 alkoxy group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C 3 -C 60 carbocyclic group, a C 1 -C 60 heterocyclic group, a C 6 -C 60 aryloxy group, a C 6 -C 60 arylthio group, a C 7 -C 60 aryl alkyl group, a C 2 -C 60 heteroaryl alkyl group, —Si(Q 11 )(Q 12 )(Q 13 ), —N(Q 11 )(Q 12 ), —B(Q 11 )(Q 12 ), —C(═O)(Q 11 ), —S(═O) 2 (Q 11 ), —P(═O)(Q 11 )(Q 12 ), or any combination thereof;
a C 3 -C 60 carbocyclic group, a C 1 -C 60 heterocyclic group, a C 6 -C 60 aryloxy group, a C 6 -C 60 arylthio group, a C 7 -C 60 aryl alkyl group, or a C 2 -C 60 heteroaryl alkyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C 1 -C 60 alkyl group, a C 2 -C 60 alkenyl group, a C 2 -C 60 alkynyl group, a C 1 -C 60 alkoxy group, a C 3 -C 60 carbocyclic group, a C 1 -C 60 heterocyclic group, a C 6 -C 60 aryloxy group, a C 6 -C 60 arylthio group, a C 7 -C 60 aryl alkyl group, a C 2 -C 60 heteroaryl alkyl group, —Si(Q 21 )(Q 22 )(Q 23 ), —N(Q 21 )(Q 22 ), —B(Q 21 )(Q 22 ), —C(═O)(Q 21 ), —S(═O) 2 (Q 21 ), —P(═O)(Q 21 )(Q 22 ), or any combination thereof; or
—Si(Q 31 )(Q 32 )(Q 33 ), —N(Q 31 )(Q 32 ), —B(Q 31 )(Q 32 ), —C(═O)(Q 31 ), —S(═O) 2 (Q 31 ), or —P(═O)(Q 31 )(Q 32 ),
Q 11 to Q 13 , Q 21 to Q 23 , and Q 31 to Q 33 may each independently be: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C 1 -C 60 alkyl group; a C 2 -C 60 alkenyl group; a C 2 -C 60 alkynyl group; a C 1 -C 60 alkoxy group; a C 3 -C 60 carbocyclic group or a C 1 -C 60 heterocyclic group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C 1 -C 60 alkyl group, a C 1 -C 60 alkoxy group, a phenyl group, a biphenyl group, or any combination thereof; a C 7 -C 60 aryl alkyl group; or a C 2 -C 60 heteroaryl alkyl group.
14 . The organic photodetector of claim 12 , wherein:
the electron transport region comprises a buffer layer, and
the buffer layer and the active layer are in direct contact with each other.
15 . The organic photodetector of claim 14 , wherein the p-type organic semiconductor comprised in the second layer has a lowest unoccupied molecular orbital (LUMO) energy level between a LUMO energy level of the n-type organic semiconductor and a LUMO energy level of a material comprised in the buffer layer.
16 . The organic photodetector of claim 1 , wherein a dark current density is about 10 −5 milliamperes per square centimeter (mA/cm 2 ) or lower at a reverse bias of about −3 volts (V).
17 . An electronic apparatus comprising the organic photodetector of claim 1 .
18 . The electronic apparatus of claim 17 , further comprising a light-emitting device.
19 . The electronic apparatus of claim 17 , further comprising a thin-film transistor.
20 . An electronic apparatus comprising:
a substrate comprising a photodetection region and a light-emitting region;
an organic photodetector disposed on the photodetection region; and
a light-emitting device disposed on the light-emitting region,
wherein the organic photodetector comprises:
a first pixel electrode;
a counter electrode facing the first pixel electrode; and
a first common layer, an active layer, and a second common layer sequentially arranged between the first pixel electrode and the counter electrode,
wherein the active layer comprises a first layer and a second layer, the first layer disposed between the first pixel electrode and the second layer, wherein:
the first layer comprises a p-type organic semiconductor and an n-type organic semiconductor, and
the second layer consists only of the p-type organic semiconductor,
wherein
the light-emitting device comprises:
a second pixel electrode;
a counter electrode facing the second pixel electrode;
and the first common layer, an emission layer, and the second common layer sequentially disposed between the second pixel electrode and the counter electrode, and wherein:
the first pixel electrode and the active layer correspond to the photodetection region,
the second pixel electrode and the emission layer correspond to the light-emitting region, and
the first common layer, the second common layer, and the counter electrode correspond to the photodetection region and the light-emitting region as a whole.