Perovskite light emitting device
A perovskite light emitting diode having degradation of the characteristics of the light emitting device, caused by PEDOT:PSS can be improved by replacing PEDOT:PSS contained in a conventional hole transport layer with an anionic conjugated polymer having ammonium-based counter ions, and the light emission characteristics can be greatly improved by passivating defects of a perovskite light emitting layer with a hole transport layer containing a conjugated polymer and increasing crystal growth.
1 . A perovskite light-emitting device comprising:
a first electrode;
a hole transport layer disposed on the first electrode;
a perovskite light-emitting layer disposed on the hole transport layer;
an electron transport layer disposed on the perovskite light-emitting layer; and
a second electrode disposed on the electron transport layer;
wherein the hole transport layer contains a compound represented by a following Chemical Formula 1,
wherein a HOMO level of the hole transport layer is in a range of 5.60 to 6.0 eV,
wherein a difference between a LUMO level of the hole transport layer and a LUMO level of the perovskite light-emitting layer is 0.3 eV or greater, and
wherein a difference between a HOMO level of the hole transport layer and a HOMO level of the perovskite light-emitting layer is 0.26 eV or lower:
wherein m is an integer between 1 and 1,000,000:
wherein each of R 1 and R 2 is independently -Ar 3 -(O—C n H 2n —X − Y + ) p ; n being is an integer between 1 and 20, and p is an integer between 1 and 3,
wherein Ar 3 is phenylene,
wherein X − is SO 3 − , and Y + is NR 3 R 4 R 5 R 6 + ,
wherein each of R 3 to R 6 is independently selected from an alkyl group having 1 to 20 carbon atoms,
wherein Ar 2 is a substituted or unsubstituted arylene.
2 . The device of claim 1 , wherein a contact angle of water on a surface of the hole transport layer is 10° or greater.
3 . The device of claim 1 , wherein a thickness of the perovskite light-emitting layer is 500 nm or smaller.
4 . The device of claim 1 , wherein the hole transport layer is subjected to post-treatment using electrical stress applied in a driving direction of the perovskite light-emitting device.
5 . The device of claim 1 , wherein the perovskite light-emitting device is encapsulated and then aged for at least 12 hours in a nitrogen atmosphere at room temperature.
6 . The device of claim 1 , wherein the compound represented by Chemical Formula 1 is the compound represented by a following compound MPS-TMA