BNSeSe MR-TADF 发光分子:硒/硒取代
BNSeSe 是硒/硒取代的 B/N 发光分子。比较同系列文献中的自旋转化、OLED 效率随亮度变化与器件寿命。
一组配套 OLED 发光体用于考察硫族原子替换如何影响自旋转换、高亮度效率和工作稳定性。
- 材料形态
- 分散在主体薄膜中的发光体
- 功能
- 三重态利用与发光
- 应用
- 绿色有机发光二极管
结构
含 Se/Se 杂原子的 B/N 骨架。这一系列在保留相关分子骨架的同时,改变自旋–轨道耦合。
性能与功能
- 激发态路径
- 单重态和三重态通过相互竞争的自旋转换与衰减通道交换布居。
- 工作负载下的表现
- 比较各报告亮度下的实测效率。
器件与加工
分子构建
已发表路线通过芳香族 C–N 偶联和含硼环的形成,构建发光体骨架。
主客体薄膜
发光体以低浓度分散在主体材料中测量,并非孤立的气相分子。
OLED 工作过程
注入电荷在发光层中产生激发态;器件测量分别报告效率和稳定性。
Measured host-film photophysics
DMIC-TRZ 主体薄膜中发光体含量 1 wt%,惰性气氛
Experimentally inferred rate from measured prompt/delayed PL lifetimes and yields; not a direct elementary-state measurement
Published 2024 calculations cite the corresponding 2022 experimental emitter; no model is fitted to device data.
| 物理量 | 数值 |
|---|---|
| 光致发光峰 | 514 nm |
| 光致发光量子产率 | 100% |
| Prompt lifetime | 1.9 ns |
| Delayed lifetime | 9.9 μs |
| Singlet–triplet gap | 0.14 eV |
| RISC rate inferred from PL | 2.00e+6 s−1 |
Observed OLED performance
Device D: 1 wt% emitter in DMIC-TRZ, 50 nm emitting layer.
Within this four-device series, faster inferred RISC accompanies better efficiency at high luminance, while the best-EQE device has a shorter reported operational lifetime.
This series is not an isolated causal test of RISC versus lifetime. Heteroatom substitution changes other molecular and device properties.
Representative device values are kept separate from ensemble means. SI tables report averages for more than fifteen devices but the downloaded curves do not include replicate-level data or pointwise error bars.
Reported LT50 values are condition-specific laboratory device measurements, not service-life predictions.
Lines connect published observations only; no model is fitted to these device curves.
| Device / emitter | EQE max / % | EQE at 1000 cd m−2 / % | EQE at 10000 cd m−2 / % | LT50 / h | EL peak / nm | EL FWHM / nm |
|---|---|---|---|---|---|---|
| D / BNSeSe | 36.8 | 34 | 21.9 | 4.1 | 512 | 48 |
Compare efficiency at the operating brightness
All four Hu devices report EQE at 1000 and 10000 cd m−2. These tabulated checkpoints support a common-luminance comparison; each device’s peak EQE is its own reference, not a shared brightness.
Absolute loss = peak EQE − checkpoint EQE, in percentage points (pp). Relative roll-off = 100 × (peak EQE − checkpoint EQE) / peak EQE, in percent. Retained peak efficiency = 100 × checkpoint EQE / peak EQE.
BNSeSe at 1000 cd m−2: EQE 34% versus peak 36.8%; the loss is 2.8 pp, relative roll-off 7.61%, and retained peak efficiency 92.39%. These calculations use representative-device values, not ensemble means.
Measured electrical operating points
Hu et al. (2022) 的 A–D 器件;相同的真空沉积层结构;DMIC-TRZ 中发光体含量为 1 wt%,发光层厚 50 nm。 The dataset contains 83 observed operating points joined by exact luminance across the Figure 3d–f source sheets; no voltage or current is interpolated.
With J in mA cm−2 and V in volts, electrical input per area is J × V in mW cm−2; multiply by 10 for W m−2. Equal voltage is not equal brightness. Switching emitters in the interactive view selects the nearest observed brightness and displays its actual value.
Source lm W−1 values are photometric luminous efficacy, not dimensionless optical power efficiency. The separate πL/(10JV) check assumes Lambertian angular emission; agreement checks arithmetic without establishing the angular pattern. The selected display domain requires L ≥ 1 cd m−2, positive V/J and EQE within 0–100%; all raw rows remain downloadable.
No pointwise experimental error bars are supplied. These bipolar-device observations do not identify mobility, injection barriers or the cause of efficiency loss.
| Device / emitter | J / mA cm−2 | L / cd m−2 | Electrical input / mW cm−2 | Source efficacy / lm W−1 |
|---|---|---|---|---|
| D / BNSeSe | 3.96408 | 3681.6488 | 15.85632 | 72.944 |
Device-ensemble evidence
Published device-ensemble summary, distinct from representative-device values and the single source curve
均值基于 15 个以上独立器件;逐条件样本数未提供。
原文未定义 ± 的统计含义。
Percentage points of EQE; not a relative percentage of the mean
These ensemble means must not silently replace the paper’s representative-device maxima or be used as pointwise error bars on the downloaded Figure 3e curves.
| Device / emitter | Peak EQE | EQE at 1000 cd m−2 | EQE at 10000 cd m−2 |
|---|---|---|---|
| D / BNSeSe | 36.40 ± 0.22 | 33.34 ± 0.28 | 21.19 ± 0.51 |
Computed excited-state model
Exact integrated three-excited-state linear kinetics from rounded published computational rates; no new experiment or electronic-structure calculation.
The model uses published elementary rates for S1, T1 and T2. dp/dt = −A p; the integrated state residence is u = A⁻¹p0. Outcome probabilities are decay rates multiplied by residence times.
For optical initial excitation p0 = (1, 0, 0), the reproduced total radiative probability is 93.26%. The measured host-film PLQY is 100%. These are calculated and measured results from different evidence contexts; agreement with a published calculation is an implementation check.
The 1:3 singlet/triplet generation ratio is an assumed spin-statistical limit, not a measurement for these devices.
The default 25% extraction and 100% charge balance are illustrative scenario assumptions. Their product with model internal emission is not measured EQE.
Added first-order triplet loss is a hypothetical sensitivity parameter; it is not a fitted TTA rate, current density, oxygen concentration, or brightness.
Removing T2→S1 is a mathematical pathway test, not the prediction of a synthesizable molecule.
Omitted processes: Bimolecular triplet–triplet and triplet–polaron annihilation; Charge transport and spatial recombination; Host/morphology changes; Optical stack and dipole orientation; Chemical degradation and operational lifetime.
No statistical confidence interval is assigned to published computed elementary rates; two-significant-figure input rounding limits output precision. Slider results are sensitivities, not confidence bounds.
| 起始态 | To S1 | To T1 | To T2 | Radiative decay | 非辐射衰减 |
|---|---|---|---|---|---|
| S1 | — | 8.70e+7 | 9.40e+8 | 2.50e+8 | 1.80e+7 |
| T1 | 1.20e+5 | — | 1.70e+9 | 4.90e+2 | 1.40e+2 |
| T2 | 1.80e+9 | 2.20e+12 | — | 9.60e+3 | 1.90e+2 |
芳基卤化物在 C–N 偶联中的作用
站内分别介绍了芳基碳–卤素键和芳香胺这两种结构特征。
这些研究先组装取代芳胺前体,再构建含硼骨架。2025 年路线使用了 Buchwald–Hartwig C–N 偶联。
苯胺用于说明芳香胺结构;已发表的合成需要具有特定取代基的前体及选择性偶联条件。
硫族元素替换与激发态动力学
元素记录将 O、S 与 Se 列为第 16 族元素。
O/S/Se 比较考察骨架内原子如何改变自旋–轨道耦合,以及涉及较高三重态的转移。解释这些变化仍需考虑分子几何和相互竞争的速率。
2024 年动力学计算包含 BNOO、BNSS 与 BNSeSe;BNSSe 列于实验比较。
共轭结构与发射能量
苯和联苯条目提供具体的芳香结构;已有低聚苯研究考察的是一组特定的吸收变化。
2025 年的分子对说明,“共轭越长、发光越红”并非普遍规则:在特定位置增加硼原子会改变电子分布,使发射蓝移。
低聚苯结果涉及另一系列分子的吸收。发射能量、前线轨道能量差和单重态–三重态能隙是不同的量。
Sources and reproducible analysis
Published measurements, source-derived rates and Mol2Mat calculations are identified separately. The downloads reproduce the analysis without claiming new synthesis, device fabrication or electronic-structure calculations.
- 分析 JSON
- 来源清单
- Measured device observations CSV
- Condition-annotated records
- Published computed elementary rates
- Efficient selenium-integrated TADF OLEDs with reduced roll-off
- Supporting information, Tables 8–10
- Figure 3 numerical source workbook
- Quantitative prediction of rate constants and its application to organic emitters
- Physical data and inferred kinetic parameters in 1 wt% DMIC-TRZ films
- Final published Figure 3: A–D device architecture and performance
- Author-shared final article, device architecture text
Density-dependent excited-state losses
conditional-normalized-steady-state-model
All defaults are illustrative dimensionless assumptions; no rate is assigned to a selected BNOO, BNSS, BNSSe or BNSeSe emitter.
Spatially uniform, steady generation in a two-excited-state kinetic system. S1/T1 are coarse-grained states, not a reduction fitted to the separate S1/T1/T2 calculation.
Fixed first-order coefficients, no state filling, heating, diffusion gradients, charge transport, polaron annihilation, phosphorescence, singlet-singlet annihilation or chemical degradation.
fS=.25 is an assumed electrical 1:3 singlet:triplet generation fraction. fS=1 describes pure singlet generation, not an entire optical experiment.
TTA f=.25 is the stated effective branch convention. It is not a measured universal spin yield.
STA destroys one singlet and leaves one triplet after rapid higher-triplet relaxation.
Both a and b scale proportionally with G for a fixed material; changing only one load is a channel-isolation counterfactual.
The interactive comparison varies dimensionless generation load kTT G / KS² and scales kST G / KS² with it. The two-state sensitivity model is separate from the material-specific three-state calculation. It does not convert a measured OLED curve into collision-rate constants.
kTT*T^2 is effective annihilating encounters per volume per time. At f=1/4 the singlet source is +(1/4)kTT*T^2 and triplet sink is -(5/4)kTT*T^2. The NET excitation-number loss is kTT*T^2, not 2*kTT*T^2.
| 方案 | 每产生一个激发所发射的光子数 | Yield / own dilute limit |
|---|---|---|
| TTA only, kRISC / KS = 0.01 | 0.5611 | 60.63% |
| TTA + STA, kST / kTT = 100 | 0.4077 | 44.06% |
| TTA only, kRISC / KS = 0.1 | 0.9435 | 98.65% |
An operando test of competing mechanisms, 2026
King et al., Uncovering the Origin of Efficiency Roll-Off in TADF OLEDs. 15 wt% 4CzIPN in mCBP; 30 nm emissive layer.
TTA was negligible in this device; STA and polaron quenching explained the measured roll-off.
SPA dominated below about 100 mA cm^-2.
STA dominated above about 100 mA cm^-2.
The adjacent normalised TTA/STA exercise is a sensitivity calculation. It neither uses these fitted coefficients as presets nor reproduces the measured 4CzIPN device, which also requires SPA, TPA, charge densities and device geometry.
The ± values below are one standard deviation from fitting. An additional estimated 20% uncertainty in generation rate is excluded. The TTA upper bound is based on the fit’s 95% confidence interval. No independent reprocessing of the source raw dataset is claimed.
| 过程 | 系数 | 证据 |
|---|---|---|
| Singlet–triplet annihilation | 3.90e-12 ± 5.00e-13 | Fit to film measurements |
| Triplet–triplet annihilation | < 8.00e-15 | Film measurements; no nonzero estimate established |
| Singlet–polaron annihilation | 6.20e-13 ± 1.00e-14 | Fit to operando device measurements |
| Triplet–polaron annihilation | 6.00e-15 ± 1.00e-15 | Fit to operando device measurements |
Evidence and limits
下方可查看 Hu et al. (2022) 的配套器件曲线,以及 Shizu and Kaji (2024) 按电子态区分的计算。
来源说明