Audit of a Near-Infrared Tandem OLED Microcavity Simulation

Park et al. (2022): real result-page screenshots for non-cavity spectra, tandem cavity modes, Ag thickness, and 710–770 nm target spectra

AuthorLuke Cole

Cell proliferation effect of deep-penetrating microcavity tandem NIR OLEDs with therapeutic trend analysis

Authors: Yongjin Park, Hye-Ryung Choi, Yongmin Jeon, Hyuncheol Kim, Jung Won Shin, Chang-Hun Huh, Kyoung-Chan Park, and Kyung-Cheol Choi

Journal: Scientific Reports 12, 10935 (2022) · Licence: CC BY 4.0

Park et al. used two tandem emission units in an Ag/Al metal microcavity to set the target peak of a near-infrared organic light-emitting diode (OLED) between 710 and 770 nm. This page compares Figures 1c, 3, 4f, S4, S6, S8, and S16 one by one. Every software image is a real Dreapex TMM result-page screenshot captured after Run or Sweep; its visible caption identifies the paper panel, quantity, and coordinate conversion that it addresses.

“Correspondence” here means that the independent variable, dependent variable, and chart type match. It does not imply numerical reproduction. The non-cavity spectra and the peak of single-unit device A are close to the paper. The tandem microcavity recovers the two diagonal mode families and their red-shift direction, while the absolute cavity positions and complete tandem-device spectra do not close quantitatively. The paper states that the complex refractive indices of all organic layers were measured by ellipsometry but does not publish those data, so the current models use public material data and the proxies listed below.

Paper figure	Published chart	Software evidence	Correspondence
Figure 1c	Measured and simulated single/tandem normalized spectra overlaid on one axis	Two `Normalized Spectrum` result pages	Split correspondence. The quantity and wavelength range match, but the software screenshots do not overlay two separate models
Figure S4	PL, Fabry–Pérot factor, two-beam factor, and final intensity	Two `Intensity` result pages	Partial correspondence. The screenshots cover only the final `Intensity`, not the first three decomposed quantities
Figures 3a–d	Narrow-range 2D intensity maps at `710`, `730`, `750`, and `770 nm`	Four separate narrow-range `Heatmap` screenshots	Direct chart-type correspondence. Each paper panel is followed by the software result at the same wavelength; coordinates use the conversion below
Figures S6a–d	Wide-range 2D intensity maps at the same four wavelengths	Four separate wide-range `Heatmap` screenshots	Direct chart-type correspondence. The UI axes are per-unit thicknesses; the paper axes are totals for both units
Figure S8	Four intensity curves for `15`, `20`, `30`, and `40 nm` Ag	One `Intensity` page with exactly those four curves visible	Direct chart-type correspondence. The curve set matches, while lineshapes and linewidths do not
Figure 4f	Normalized spectra of devices A, B, and C overlaid on one axis	Three `Normalized Spectrum` result pages	Split correspondence. Each screenshot covers one device; the software does not overlay separate models
Figure S16	Normalized spectra of four target devices	One four-curve `Normalized Spectrum` sweep page	Direct chart-type correspondence. The scan parameters match, but the software does not produce the paper's four NIR main peaks

Structure

Tandem microcavity devices B and C differ only in the Ag-anode thickness. Dreapex TMM Intensity calculates radiation toward the Top Medium end of the list. The software stack therefore starts on the emitting side with Glass substrate, followed by the Ag anode, two emission units, Liq, and the Al cathode. Both surrounding media are Air, and the 1 mm glass layer is marked Inco..

Layer	Thickness	Layer state
Glass substrate	`1 mm`	`Inco.`
Ag	Device B `30 nm`; device C `20 nm`	None
MoO₃	`10 nm`	None
NPB	`120 nm`	None
Bebq₂:Ir(piq)₃	`30 nm`	`Emis.`
Alq₃:LiH	`40 nm`	None
Liq	`1 nm`	None
Al	`100 nm`	None

MoO₃, NPB, Bebq₂:Ir(piq)₃, and Alq₃:LiH form one Layer Group with Repeat Count set to 2. The Figure 3 and Figure S6 sweeps change the NPB and Alq₃:LiH thicknesses inside that group so that both emission units remain identical.

Complete tandem microcavity structure page, with glass in the first emitting-side row and the emission unit repeated twice — Configuration evidence, not a paper-result Figure. The Structure page shows the emitting-side glass, Ag anode, two repeats of Tandem emission unit, Liq, and the Al cathode.

Layer Group dialog for the tandem emission unit, showing its four layers and two repeats — Configuration evidence, not a paper-result Figure. The Layer Group dialog shows MoO₃, NPB, EML, and ETL and repeats the same emission unit twice.

The non-cavity baseline replaces Ag with an assumed 150 nm ITO layer. NPB and Alq₃ are 40 nm and 20 nm in the single device; the non-cavity tandem device contains the same emission unit twice. Device A uses 30 nm Ag, 90 nm NPB, and 40 nm Alq₃ with one emission unit.

The paper's Methods give layer thicknesses and material names and state that $n$ and $k$ for every organic layer were measured by ellipsometry. The arrays are not published. This audit uses $n=1.52$ for glass and public dispersive entries from the Dreapex TMM refractive-index database for Ag, MoO₃, NPB, Alq₃, and Al. Transparent Alq₃ proxies for Bebq₂:Ir(piq)₃, and Alq₃:LiH uses the Alq₃ optical data. Neither refractive indices nor thicknesses were adjusted to register a paper peak.

Emitter and Sweep Settings

Each emissive layer contains an emitter at its centre with a Delta distribution, and the UI dipole-orientation field is set to Isotropic. The emission spectrum is extracted from the Ir(piq)₃ thin-film photoluminescence curve in paper Figure S1. The paper directly multiplies this normalized PL ordinate by its cavity gain and does not say whether the spectrum is photon counts or radiant power, so it is entered as Power here. The two tandem emission units have equal weights; quantum efficiency, conversion efficiency, and multiplier are all 1.

Setting	Value
Detector	Emission `Intensity`
Emission angle	`Single`, `0°`
Figures 1c and 4f	`400–800 nm` or `500–800 nm`, `2 nm` step
Figure S8	Ag `15–40 nm`, `5 nm` step; wavelength `550–800 nm`, `2 nm` step
Figure S16	Per-unit NPB `115–130 nm`, `5 nm` step; wavelength `500–800 nm`, `2 nm` step
Figure 3	Per-unit NPB `5–140 nm` and ETL `5–50 nm`, both in `5 nm` steps; single target wavelength
Figure S6	Per-unit NPB `5–190 nm` and ETL `15–200 nm`, both in `5 nm` steps; single target wavelength

Expanded Intensity settings in the Emission lane, showing the single angle and wavelength sweep — Configuration evidence, not a paper-result Figure. The Emission Intensity detector uses a single 0° angle; each Figure recipe sets its wavelength range.

The four software sweep configurations follow. Total, Line, and Heatmap are selected later on the result pages.

NPB-thickness sweep for the 710–770 nm target devices — Configuration evidence for Figure S16. Per-unit NPB runs from 115 to 130 nm; the four values represent the paper's 710, 730, 750, and 770 nm target devices.

Ag-thickness sweep settings — Configuration evidence for Figure S8. The software evaluates Ag from 15 to 40 nm in 5 nm steps; the result screenshot uses the legend to show only the paper's 15, 20, 30, and 40 nm curves.

Two-dimensional NPB and ETL sweep settings for the Figure 3 design window — Configuration evidence for Figure 3. Per-unit NPB spans 5–140 nm and ETL spans 5–50 nm, mapping to total HTL 30–300 nm and total ETL 10–100 nm.

Two-dimensional NPB and ETL sweep for the Figure S6 cavity maps — Configuration evidence for Figure S6. Per-unit NPB spans 5–190 nm and ETL spans 15–200 nm, mapping to total HTL and ETL ranges of 30–400 nm.

Non-Cavity Normalized Spectra (Figure 1c)

Figure 1c gives measured normalized electroluminescence spectra for the single and tandem non-cavity devices, with the paper's own optical simulations overlaid. The measured single-device peak is 630.1 nm. The tandem peak is 626.4 nm, with a broader long-wavelength shoulder.

Paper Figure 1c, measured and simulated normalized electroluminescence spectra of the non-cavity single and tandem devices — Paper Figure 1c. The non-cavity tandem device has a broader long-wavelength shoulder.Yongjin Park et al., Scientific Reports 12, 10935 (2022), Figure 1c CC BY 4.0

Dreapex TMM normalized emission spectrum of the non-cavity single device — Split correspondence to the Single curve in Figure 1c. This software screenshot shows only the non-cavity single-device Normalized Spectrum; the paper overlays Single, Tandem, and both simulated curves on one axis.

Dreapex TMM normalized emission spectrum of the non-cavity tandem device — Split correspondence to the Tandem curve in Figure 1c. The wavelength range and normalized ordinate match the paper, but the result page shows one imported model and therefore does not reproduce the paper's four-curve layout.

Quantity	Paper measurement	Dreapex TMM	Difference
Single-device peak	`630.1 nm`	`631.7 nm`	`+1.6 nm`
Single-device envelope FWHM	`88.0 nm`	`80.9 nm`	`−7.1 nm`
Single-device normalized lineshape RMS	Not applicable	`8.1%`	Not applicable
Tandem-device peak	`626.4 nm`	`632.7 nm`	`+6.3 nm`
Tandem-device envelope FWHM	`102.6 nm`	`99.5 nm`	`−3.1 nm`
Tandem-device normalized lineshape RMS	Not applicable	`4.1%`	Not applicable

The RMS values compare the extracted paper measurement and the exported normalized software intensity point by point over 580–778 nm. The two screenshots address the Single and Tandem objects in Figure 1c separately; this split presentation is not the same as reproducing the paper's four-curve layout.

Final Intensity and Decomposition Boundary (Figure S4)

Figure S4 separates the paper model into PL, Fabry–Pérot factor, two-beam factor, and final intensity. Dreapex TMM Intensity reports the complete emission intensity and does not expose the first three paper-specific factors as separate result charts. The two software screenshots below therefore correspond only to the final Intensity curve in each Figure S4 panel.

Paper Figure S4, PL, Fabry–Pérot factor, two-beam factor, and final intensity for the non-cavity single and tandem devices — Paper Figure S4. The tandem structure raises the long-wavelength response in the final intensity.Yongjin Park et al., Supporting Information, Figure S4 CC BY 4.0

Raw Dreapex TMM Intensity result for the non-cavity single device — Partial correspondence to Figure S4a. The screenshot addresses the final Intensity in the single-device panel, not the PL, Fabry–Pérot factor, or two-beam factor curves.

Raw Dreapex TMM Intensity result for the non-cavity tandem device — Partial correspondence to Figure S4b. The screenshot addresses the final Intensity in the tandem-device panel, not the paper's three separately plotted factors.

Coordinate Conversion for the 2D Cavity Maps

Figures 3 and S6 use the total thicknesses of the two HTLs and two ETLs in the tandem cavity. A software Layer Group sweep varies the NPB and ETL thickness in one emission unit, so the paper coordinates $X$ and $Y$ relate to the software inputs as

X = 2\left(10\ \mathrm{nm} + d_{\mathrm{NPB}}\right), \qquad Y = 2d_{\mathrm{ETL}}.

Here, $X$ is the paper's total HTL thickness, $Y$ is its total ETL thickness, and $d_{\mathrm{NPB}}$ and $d_{\mathrm{ETL}}$ are the NPB and ETL thicknesses in one emission unit. The fixed 10 nm is the MoO₃ layer in each unit. Every thickness is in nm. Each paper panel below sits immediately before the software screenshot with the same wavelength and scan range.

Design-Window Cavity Maps (Figure 3)

Figure 3 spans approximately 30–300 nm total HTL and 10–100 nm total ETL. The matching software sweep uses per-unit NPB 5–140 nm and ETL 5–50 nm. The four marked paper design points map to per-unit NPB values of 115, 120, 125, and 130 nm, respectively, with ETL fixed at 40 nm.

710 nm: Figure 3a

Paper Figure 3a, two-dimensional total-HTL and total-ETL emission-intensity map at 710 nm — Paper Figure 3a. The marked 710 nm point uses total HTL 250 nm and total ETL 80 nm.Yongjin Park et al., Scientific Reports 12, 10935 (2022), Figure 3a CC BY 4.0

Dreapex TMM Figure 3-range two-dimensional Intensity Heatmap at 710 nm — Direct chart-type comparison with Figure 3a. Software NPB 5–140 nm maps to paper total HTL 30–300 nm, and software ETL 5–50 nm maps to paper total ETL 10–100 nm; the marked paper point maps to 115 nm, 40 nm in the UI.

730 nm: Figure 3b

Paper Figure 3b, two-dimensional total-HTL and total-ETL emission-intensity map at 730 nm — Paper Figure 3b. The marked 730 nm point uses total HTL 260 nm and total ETL 80 nm.Yongjin Park et al., Scientific Reports 12, 10935 (2022), Figure 3b CC BY 4.0

Dreapex TMM Figure 3-range two-dimensional Intensity Heatmap at 730 nm — Direct chart-type comparison with Figure 3b. The coordinate conversion is the same as for Figure 3a; the marked paper point maps to per-unit NPB 120 nm and ETL 40 nm.

750 nm: Figure 3c

Paper Figure 3c, two-dimensional total-HTL and total-ETL emission-intensity map at 750 nm — Paper Figure 3c. The marked 750 nm point uses total HTL 270 nm and total ETL 80 nm.Yongjin Park et al., Scientific Reports 12, 10935 (2022), Figure 3c CC BY 4.0

Dreapex TMM Figure 3-range two-dimensional Intensity Heatmap at 750 nm — Direct chart-type comparison with Figure 3c. The coordinate conversion is the same as for Figure 3a; the marked paper point maps to per-unit NPB 125 nm and ETL 40 nm.

770 nm: Figure 3d

Paper Figure 3d, two-dimensional total-HTL and total-ETL emission-intensity map at 770 nm — Paper Figure 3d. The marked 770 nm point uses total HTL 280 nm and total ETL 80 nm.Yongjin Park et al., Scientific Reports 12, 10935 (2022), Figure 3d CC BY 4.0

Dreapex TMM Figure 3-range two-dimensional Intensity Heatmap at 770 nm — Direct chart-type comparison with Figure 3d. The coordinate conversion is the same as for Figure 3a; the marked paper point maps to per-unit NPB 130 nm and ETL 40 nm.

All four software maps and Figures 3a–d contain two bright ridges that descend from left to right, and both ridges shift toward thicker NPB as the target wavelength increases. Their absolute positions do not land on the marked paper points. At a paper total ETL thickness of 80 nm, the right-hand ridge near the design point gives:

Target wavelength	Paper total HTL	Dreapex TMM total HTL	Difference
`710 nm`	`250 nm`	`227.9 nm`	`−22.1 nm`
`730 nm`	`260 nm`	`239.4 nm`	`−20.6 nm`
`750 nm`	`270 nm`	`250.2 nm`	`−19.8 nm`
`770 nm`	`280 nm`	`261.0 nm`	`−19.0 nm`

Wide-Range Cavity Maps (Figure S6)

Figure S6 extends both total HTL and total ETL to 30–400 nm. The software uses per-unit NPB 5–190 nm and ETL 15–200 nm, which map to the same total-thickness ranges. The four pairs below retain the one-panel-to-one-screenshot order.

710 nm: Figure S6a

Paper Figure S6a, wide-range two-dimensional emission-intensity map at 710 nm — Paper Figure S6a. The 710 nm map scans total HTL and total ETL from 30 to 400 nm.Yongjin Park et al., Supporting Information, Figure S6a CC BY 4.0

Dreapex TMM wide-range two-dimensional Intensity Heatmap at 710 nm — Direct chart-type comparison with Figure S6a. Software NPB 5–190 nm maps to total HTL 30–400 nm, and software ETL 15–200 nm maps to total ETL 30–400 nm.

730 nm: Figure S6b

Paper Figure S6b, wide-range two-dimensional emission-intensity map at 730 nm — Paper Figure S6b. Both mode families shift toward thicker transport layers relative to Figure S6a.Yongjin Park et al., Supporting Information, Figure S6b CC BY 4.0

Dreapex TMM wide-range two-dimensional Intensity Heatmap at 730 nm — Direct chart-type comparison with Figure S6b. The software uses the same range and coordinate conversion as Figure S6a.

750 nm: Figure S6c

Paper Figure S6c, wide-range two-dimensional emission-intensity map at 750 nm — Paper Figure S6c. The paper labels the first-order ridge at low thickness and two second-order ridges.Yongjin Park et al., Supporting Information, Figure S6c CC BY 4.0

Dreapex TMM wide-range two-dimensional Intensity Heatmap at 750 nm — Direct chart-type comparison with Figure S6c. The software shows multiple diagonal ridges with the same orientation; their absolute positions remain below the paper values in the table above.

770 nm: Figure S6d

Paper Figure S6d, wide-range two-dimensional emission-intensity map at 770 nm — Paper Figure S6d. The ridges continue moving toward thicker HTL and ETL at 770 nm.Yongjin Park et al., Supporting Information, Figure S6d CC BY 4.0

Dreapex TMM wide-range two-dimensional Intensity Heatmap at 770 nm — Direct chart-type comparison with Figure S6d. The software retains the two principal mode families and their shift toward thicker layers as wavelength increases.

With all eight Figure S6 images aligned by wavelength, Dreapex TMM reproduces the number of mode-ridge families, their slope, and their red-shift direction. The absolute ridge coordinates retain a 19.0–22.1 nm total-HTL difference.

Ag Thickness and Figure S8

Paper Figure S8 changes the Ag anode in the same tandem cavity to 15, 20, 30, and 40 nm. The paper curves narrow as Ag becomes thicker. Their NIR peak intensity first rises, reaches its maximum at 30 nm, and then falls at 40 nm.

Paper Figure S8, tandem microcavity electroluminescence spectra for different Ag-anode thicknesses — Paper Figure S8. The spectrum narrows as Ag increases from 15 to 40 nm, with the largest peak intensity near 30 nm.Yongjin Park et al., Supporting Information, Figure S8 CC BY 4.0

Dreapex TMM Intensity curves for 15, 20, 30, and 40 nm Ag — Direct chart-type comparison with Figure S8. The result-page legend shows the raw Intensity curves for 15, 20, 30, and 40 nm Ag; the intermediate 25 and 35 nm calculations are hidden.

Ag thickness	Paper relative NIR peak	Dreapex TMM	Paper FWHM	Dreapex TMM envelope FWHM
`15 nm`	`0.754`	`0.773`	`60 nm`	`124.2 nm`
`20 nm`	`0.983`	`0.926`	`30 nm`	`184.3 nm`
`30 nm`	`1.000`	`1.000`	`19 nm`	`30.6 nm`
`40 nm`	`0.649`	`0.731`	`14 nm`	`21.5 nm`

Each relative-intensity set is normalized to its own 30 nm result, giving four differences between 0.000 and 0.082. The software result also shows stronger NIR narrowing with thicker Ag. The 15 nm and 20 nm results contain broad lobes absent from the paper, so their envelope FWHM values do not describe the same isolated peak.

Devices A/B/C and Figure 4f

Figure 4f gives measured normalized electroluminescence spectra for three finished devices. A has one emission unit and 30 nm Ag. B has two units and 30 nm Ag. C has two units and 20 nm Ag. Their published peaks are 727, 727, and 732 nm.

Paper Figure 4f, measured normalized electroluminescence spectra of microcavity devices A, B, and C — Paper Figure 4f. All three main peaks are near 730 nm, and device B has the narrowest spectrum.Yongjin Park et al., Scientific Reports 12, 10935 (2022), Figure 4f CC BY 4.0

Dreapex TMM normalized emission spectrum of microcavity device A — Split correspondence to device A in Figure 4f. This screenshot shows the single-unit, 30 nm Ag model alone; the paper overlays A, B, and C on one axis.

Dreapex TMM normalized emission spectrum of microcavity device B — Split correspondence to device B in Figure 4f. This model has two emission units and 30 nm Ag; its NIR main peak is 763.0 nm rather than the paper's 727 nm.

Dreapex TMM normalized emission spectrum of microcavity device C — Split correspondence to device C in Figure 4f. This model has two emission units and 20 nm Ag; the software produces several strong lobes absent from Figure 4f.

Device	Paper peak	Dreapex TMM peak	Peak difference	Paper FWHM	Dreapex TMM envelope FWHM
A	`727 nm`	`724.1 nm`	`−2.9 nm`	`52 nm`	`74.5 nm`
B	`727 nm`	`763.0 nm`	`+36.0 nm`	`23 nm`	`30.6 nm`
C	`732 nm`	`767.2 nm`	`+35.2 nm`	`34 nm`	`184.3 nm`

The absolute peak of device A is close to the paper, while its linewidth is 22.5 nm larger. The NIR main peak of B is substantially red-shifted. C has several strong lobes and stays above half maximum over a broad interval, so its 184.3 nm envelope width does not represent the isolated NIR peak reported in the paper.

Target-Wavelength Devices and Figure S16

Paper Figure S16 gives measured devices targeting 710, 730, 750, and 770 nm. Paper Table 1 assigns per-unit NPB thicknesses of 115, 120, 125, and 130 nm, respectively, with a fixed 40 nm ETL.

Paper Figure S16, measured normalized electroluminescence spectra of four target-wavelength NIR OLEDs — Paper Figure S16. Increasing the HTL moves the measured peak from 710 to 770 nm.Yongjin Park et al., Supporting Information, Figure S16 CC BY 4.0

Dreapex TMM normalized emission spectra from the sweep over four NPB thicknesses — Direct chart-type comparison with Figure S16. One Sweep result page shows four Normalized Spectrum curves for per-unit NPB 115, 120, 125, and 130 nm; the 750 and 770 nm designs have global peaks in the visible range, so the numerical result does not reproduce the paper figure.

Paper target peak	Per-unit NPB	Dreapex TMM NIR local peak	Difference	Local peak relative to global peak
`710 nm`	`115 nm`	`746.8 nm`	`+36.8 nm`	`1.000`
`730 nm`	`120 nm`	`763.0 nm`	`+33.0 nm`	`1.000`
`750 nm`	`125 nm`	`778.4 nm`	`+28.4 nm`	`0.688`
`770 nm`	`130 nm`	`797.5 nm`	`+27.5 nm`	`0.445`

The software results preserve the red-shift order of the NIR local peak as NPB becomes thicker. The global peaks of the 750 nm and 770 nm models are at 540.4 and 550.8 nm, so the NIR features shown in the screenshot are only local peaks. This differs from the four NIR main peaks in the paper.

Deviation Boundaries

The measured organic-layer $n$ and $k$ are absent from the publication. The 19.0–22.1 nm Figure S6 thickness differences and the approximately 35 nm tandem-device peak differences both indicate an optical-thickness mismatch; the current evidence cannot assign it uniquely to one material.
Alq₃ proxies for Bebq₂:Ir(piq)₃, and Alq₃:LiH also uses Alq₃ data. These proxies preserve the basic cavity behaviour of transparent organic layers but not the measured dispersion of the paper samples.
The paper does not give the relative emission strengths or actual recombination positions of the two emission units. This audit uses equal weights at both layer centres; both quantities change the combined tandem spectrum.
The paper equations first add the Fabry–Pérot terms of the two units and separately add their two-beam terms before multiplying those sums. Dreapex TMM calculates the radiation from each emissive layer and then adds the two contributions. These definitions can assign different weights to lobes in a strong microcavity.
Agreement in the Figure S8 relative NIR-intensity trend does not establish agreement of the complete spectra. The matching Figure S6 mode shape also does not replace the absolute-coordinate check.

This page retains the unresolved results so that the publication figures can be compared directly with the software result pages. If the measured organic-layer ellipsometry data become available, the same layer thicknesses, emission positions, and sweep grids can be rerun to test the absolute tandem-microcavity peaks.

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