| 主权项 |
1. A polymer blend comprising
a first polymer comprising a hole transporting unit comprising a group B and a group Ah, wherein Ah is a group having hole transport property; a second polymer comprising an electron transporting unit comprising a group B and a group Ae, wherein Ae is a group having electron transport property, and an exciton formation unit comprising a group B and a group Aex, wherein Aex is a group having exciton formation property, and optionally comprising one or more further emissive and/or exciton formation units; wherein the group B denotes, independently of one another, identical or different backbone groups; wherein the first polymer comprises one or more identical or different groups of formula (II) as hole transporting groups Ah wherein Y is N, P, P═O, PF2, P═S, As, As═O, As═S, Sb, Sb═O, or Sb═S, Ar1 is identically or differently, independently if in different repeat units, a single bond or an optionally substituted mononuclear or polynuclear aryl group; Ar2 is identically or differently, independently if in different repeat units, an optionally substituted mononuclear or polynuclear aryl group; Ar3 is identically or differently, independently if in different repeat units, an optionally substituted mononuclear or polynuclear aryl group, which may be optionally substituted by a bridging group linking different chain residues of formula (II); and m is 1, 2, or 3; and wherein the ratio of groups of formula (II) in the first polymer is from 10 to 80 mol %; wherein the second polymer comprises one or more identical or different groups of formula (I) as electron transporting groups Ae wherein A, B, and B′ are, independently of each other, and in the case of multiple occurrences, independently of one another, a divalent group selected from the group consisting of —CR1R2—, —NR1—, —PR1—, —O—, —S—, —SO—, —SO2—, —CO—, —CS—, —CSe—, —P(═O)R1—, —P(═S)R1—, and —SiR1R2—; R1 and R2 are, identically or differently, independently of each other, H, halogen, —CN, —NC, —NCO, —NCS, —OCN, —SCN, —C(═O)NR0R00, —C(═O)X, —C(═O)R0, —NH2, —NR0R00, —SH, —SR0, —SO3H, —SO2R0, —OH, —NO2, —CF3, —SF5, optionally substituted silyl, or carbyl or hydrocarbyl having 1 to 40 C atoms, wherein said carbyl or hydrocarbyl are optionally substituted and optionally comprise one or more hetero atoms; X is halogen; R0 and R00 are, independently of each other, H or an optionally substituted carbyl or hydrocarbyl group optionally comprising one or more hetero atoms; g and h are, independently, 0 or 1, wherein when g is 0, h is 1 and when g is 1, h is 0; m is an integer greater than or equal to 1; Ar1 and Ar2 are, independently of each other, a mono- or polynuclear aryl or heteroaryl optionally substituted; a and b are, independently of each other, 0 or 1; wherein the ratio of groups of formula (I) in the second polymer is from 1 to 95 mol %; wherein the second polymer comprises one or more identical or different groups of formula (II) as exciton formation groups Aex wherein Y is N, P, P═O, PF2, P═S, As, As═O, As═S, Sb, Sb═O, or Sb═S, Ar1 is identically or differently, independently if in different repeat units, a single bond or an optionally substituted mononuclear or polynuclear aryl group; Ar2 is identically or differently, independently if in different repeat units, an optionally substituted mononuclear or polynuclear aryl group; Ar3 is identically or differently, independently if in different repeat units, an optionally substituted mononuclear or polynuclear aryl group, which may be optionally substituted by a bridging group linking different chain residues of formula (II); and m is 1, 2, or 3; and wherein the ratio of groups of formula (II) in the second polymer is from 0.01 to 10 mol %; with the proviso that a blend that comprises (1) a polymer comprising substituted or unsubstituted fluorene and triarylamine units and (2) a polymer comprising substituted or unsubstituted fluorene and benzothiadiazole units is excluded; wherein each of said units has a HOMO and a LUMO; wherein the difference between the HOMO and the LUMO of each unit constitutes an energy gap; wherein the HOMO and LUMO of said hole transporting unit comprising groups B and Ah is based on a trimer of structure -B-Ah-B-, the HOMO and LUMO of said electron transporting unit comprising groups B and Ae is based on a trimer of structure -B-Ae-B-, and the HOMO and LUMO of said exciton formation unit comprising groups B and Aex is based on a trimer of structure -B-Aex-B-; wherein the HOMO of both trimers -B-Ah-B- and -B-Aex-B- are at least 0.2 eV higher than the HOMO of -B-Ae-B-. |
