Test device and test method thereof

1. A test device, comprising a first electrode, an electron transport unit, a charge generation layer, a hole transport unit and a second electrode which are stacked; and

wherein the charge generation layer comprises an N-type doped layer and a P-type doped layer which are stacked, the N-type doped layer is adjacent to the electron transport unit, and the P-type doped layer is adjacent to the hole transport unit;

wherein the electron transport unit is directly attached between the first electrode and the charge generation layer, the charge generation layer is directly attached between the electron transport unit and the hole transport unit, and the hole transport unit is directly attached between the second electrode and the charge generation layer.

2. The test device according to claim 1 , wherein the first electrode comprises an anode and the second electrode comprises a cathode.

3. The test device according to claim 1 , wherein the first electrode comprises a cathode and the second electrode comprises an anode.

4. The test device according to claim 1 , wherein the electron transport unit comprises an electron injection layer and an electron transport layer stacked between the first electrode and the N-type doped layer, the electron injection layer is adjacent to the first electrode, the electron transport layer is adjacent to the N-type doped layer; and

the hole transport unit comprises a hole injection layer and a hole transport layer stacked between the second electrode and the P-type doped layer, the hole injection layer is adjacent to the second electrode, the hole transport layer is adjacent to the P-type doped layer.

5. The test device according to claim 4 , wherein a material of the electron injection layer is a metal or a metallic compound having a low work function.

6. The test device according to claim 1 , wherein the N-type doped layer is configured to generate electron carriers, and the P-type doped layer is configured to generate hole carriers.

7. The test device according to claim 1 , wherein a host material of the N-type doped layer is one or more of bathocuproine (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), 4,6-bis (3,5-bis (3-Pyridyl)phenyl)-2-methylpyrimidine (B3PYMPM), 1,3,5-tris (3-(3-pyridyl) phenyl) benzene (TmPyPB).

8. The test device according to claim 1 , wherein a N-type doping material of the N-type doped layer is one or more of lithium (Li), cesium (Cs), ytterbium (Yb), and lithium fluoride (LiF).

9. The test device according to claim 1 , wherein a host material of the P-type doped layer is one or more of N,N′-bis (naphthalene-2-yl)-N,N′-bis (phenyl)biphenyl-4,4′-diamine (NPB), 4,4′,4″-tris (carbazol-9-yl) triphenylamine (TCTA), 4,4′-cyclohexylbis [N,N-bis (4-methylphenyl)] aniline (TAPC), 1,3-dicarbazol-9-ylbenzene (mCP).

10. The test device according to claim 1 , wherein a P-type doping material of the P-type doped layer is one or more of molybdenum trioxide (MoO 3 ), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinodimethane (F4-TCNQ).

11. A test method, comprising:

providing a plurality of the test devices of claim 1 , the charge generation layer of each test device having a variable parameter, and values of the variable parameters of the plurality of the test devices being different;

applying a test voltage between the first electrode and the second electrode of each test device to cause the charge generation layer to generate a current, detecting the current flowing through each test device, and drawing a voltage-current curve according to the current varying with the test voltage; and/or

detecting a voltage of each test device under a fixed current density at a preset temperature, and drawing a voltage-time curve according to the voltage varying with the time;

determining an optimal value of the variable parameter according to the voltage-current curve and/or the voltage-time curve.

12. The test method according to claim 11 , wherein the determining the optimal value of the variable parameter comprises selecting the optimal value of the variable parameter from the values of the variable parameters of the plurality of the test devices.

13. The test method according to claim 11 , wherein the variable parameter is any one of an N-type doping material of the N-type doped layer, an N-type doping concentration, a thickness of the N-type doped layer, a P-type doping material of the P-type doped layer, a P-type doping concentration, and a thickness of the P-type doped layer.

14. The test method according to claim 11 , wherein the first electrode is an anode, and the second electrode is a cathode;

the applying the test voltage between the first electrode and the second electrode of each test device comprises:

configuring the test voltage as a forward voltage to cause the charge generation layer to generate a first internal current, detecting the first internal current of the test device, and drawing the voltage-current curve according to the first internal current varying with the forward voltage.

15. The test method according to claim 11 , wherein the first electrode is a cathode and the second electrode is an anode;

the applying the test voltage between the first electrode and the second electrode of each test device comprises:

configuring the test voltage as a reverse voltage to cause the charge generation layer to generate a second internal current, detecting the second internal current of the test device, and drawing the voltage-current curve according to the second internal current varying with the reverse voltage.

16. The test method according to claim 15 , further comprising:

applying a break-over voltage between the anode and the cathode of each test device to make each test device turned on, generating, by the anode and the cathode, an external current under an action of the break-over voltage, detecting the external current of each test device and drawing a relationship curve of the external current and the break-over voltage;

determining the optimal value of the variable parameter according to the second internal current and the external current; and

when the test voltage is the same as the break-over voltage, if a difference value between the second internal current and the external current is less than a preset value, determining a value of the variable parameter of the corresponding test device as the optimal value.

17. The test method according to claim 11 , wherein the preset temperature comprises a first preset temperature and a second preset temperature, and the first preset temperature is greater than the second preset temperature;

the detecting the voltage of each test device under the fixed current density and drawing the voltage-time curve according to the voltage varying with the time comprises:

detecting the voltages of each test device under the fixed current density at the first preset temperature and the second preset temperature respectively, and drawing the voltage-time curve according to the voltage varying with the time.

18. The test method according to claim 17 , wherein when a voltage rise amplitude is less than 1.5V within 1000 hours at the first preset temperature, determining the value of the variable parameter of the corresponding test device as the optimal value according to the voltage-time curve.

19. The test method according to claim 18 , wherein when the voltage rise amplitude is less than 1.5V within 10,000 hours at the second preset temperature, determining the value of the variable parameter of the corresponding test device as the optimal value according to the voltage-time curve.

20. A test device, comprising a first electrode, an electron transport unit, a charge generation layer, a hole transport unit and a second electrode which are stacked; and

wherein the charge generation layer comprises an N-type doped layer and a P-type doped layer which are stacked, the N-type doped layer is adjacent to the electron transport unit, and the P-type doped layer is adjacent to the hole transport unit;

wherein the first electrode is an anode and the second electrode is a cathode, the charge generation layer is configured to generate a first internal current when a test voltage applied between the first electrode and the second electrode is a forward voltage, to allow drawing a voltage-current curve according to the first internal current varying with the forward voltage; or

wherein the first electrode is a cathode and the second electrode is an anode, the charge generation layer is configured to generate a second internal current when a test voltage applied between the first electrode and the second electrode is a reverse voltage, to allow drawing a voltage-current curve according to the second internal current varying with the reverse voltage.