1 引言
2 结果与讨论
2.1 目标化合物的合成与表征
2.2 热物理性质
2.3 光物理性质
图2 室温下甲苯溶液中紫外-可见吸收光谱和荧光发射光谱图Figure 2 Ultraviolet-visible absorption spectra and fluorescence emission spectra at room temperature in toluene solution |
表1 光物理性能Table 1 Summary of optical properties |
| Compound | λabs a/nm | λPL solution b/film c (nm) | FWHM solution b/film c (nm) | τPF d/τDF e (ns/μs) | EHOMO f/ELUMO g (eV) | Eg h/eV | PLQY i/% |
|---|---|---|---|---|---|---|---|
| PhPX-CN | 284, 324, 396 | 513/518 | 89/91 | 8.11/9.50 | -5.22/-2.98 | 2.24 | 67 |
| PhAd-CN | 385 | 502/522 | 80/90 | 29.52/9.11 | -5.05/-2.78 | 2.28 | 52 |
| PhDPA-CN | 294, 376 | 496/510 | 83/85 | 14.01/10.95 | -5.30/-2.97 | 2.33 | 59 |
| PhCz-CN | 288, 356 | 440/470 | 75/94 | 19.74/9.60 | -5.66/-2.98 | 2.68 | 45 |
a Measured in toluene (10−5 mol•L−1) at room temperature; b Measured in toluene (10−5 mol•L−1) at room temperature; c TADF materials were doped into the CBP film at 15% (w) at room temperature and nitrogen. d,e Lifetime of the prompt and delayed components as TADF materials was doped into the CBP film at 15% (w); f HOMOs were calculated from cyclic voltammetry (CV) data, EHOMO=-(Eox-EFc/Fc++4.8) eV; g LUMOs were calculated from CV data, ELUMO=-(Ered-EFc/Fc++4.8) eV; h Eg=ELUMO-EHOMO; i The PLQY in toluene solution. |
2.4 电化学性质
2.5 理论计算
2.6 电致发光性能研究
图8 器件结构及功能层材料的分子结构式与能级图Figure 8 Molecular structural formulas and energy level diagrams of device structures and functional layer materials |
图9 A3和B3的(a) EL光谱图, (b)电流密度-电压-亮度特性曲线, (c) EQE与亮度特性曲线和(d) CE、PE与亮度特性曲线Figure 9 (a) EL spectra, (b) current density-voltage-luminance curves, (c) EQE-L curves of devices and (d) current efficiency-luminance characteristics, and power efficiency-luminance characteristics of A3 and B3 |
表2 基于PhDPA-CN和PhCz-CN器件的电致发光性能Table 2 Electroluminescent performance of devices based on PhDPA-CN and PhCz-CN |
| Device | Vona/V | Lmax b/ (cd•m−2) | EQEmax c/% | CEmax d/ (cd•A−1) | PEmax e/ (lm•W−1) | λEL f/ nm | FWHM/nm |
|---|---|---|---|---|---|---|---|
| A1 | 5.5 | 1106 | 6.52 | 18.03 | 9.44 | 500 | 84 |
| A2 | 5.0 | 1253 | 6.85 | 19.85 | 11.34 | 508 | 86 |
| A3 | 5.0 | 1503 | 6.83 | 20.13 | 11.50 | 512 | 87 |
| B1 | 7.0 | 340 | 1.14 | 1.32 | 0.59 | 464 | 96 |
| B2 | 6.0 | 426 | 1.72 | 2.11 | 1.11 | 468 | 85 |
| B3 | 6.0 | 712 | 3.04 | 6.26 | 3.27 | 476 | 112 |
a Turn-on voltage at 1 cd•m−2; b Maximum luminance; c Maximum power efficiency; d Maximum current efficiency; e Maximum power efficiency; f EL peak wavelength. |