Display paper briefing, 7 to 13 September
Twelve display-related papers, briefly introduced, picked out of 1,337 published in 28 major journals from 7 to 13 September and narrowed to 98. Green stood out this week: three different materials, an organic emitter, an inorganic phosphor and cadmium-free quantum dots, appeared side by side, all aimed at the same narrower, purer green.
From Monday 7 September to Sunday 13 September 2026, 1,337 papers published in 28 major journals were checked in full and narrowed to 98 with a display connection. One of those, which used Micro-LED display pixels for optical communication and ranging at the same time, is covered as a separate in-depth article, and 12 are introduced briefly here.
This week what stood out was green. Three different materials, an organic emitter, an inorganic phosphor and cadmium-free quantum dots, appeared side by side in a single week, all heading for the same target, a narrower and purer green.
Next most common was work on making pixels smaller. Colour changed through nanowire diameter, carbon nanotube transistors placed directly on a Micro-LED, and quantum dots printed out as 20-micrometre pixels.
1. A narrow green TADF made by extending a blue framework
Advanced Optical Materials · 09.07 · Thi Na Le, Department of Chemistry, Gyeongsang National University
Multi-resonance thermally activated delayed fluorescence (MR-TADF) emitters have narrow emission lines and so high colour purity. In green, though, cases that push the CIE y coordinate close to the BT.2020 target (0.797) are still rare.
The team attached phenylcarbazole, xylene and t-butyl groups to the widely used blue DABNA framework. Extending π conjugation moved emission to green, while aggregation between molecules and the formation of isomers were both blocked.
The new emitter, xy-BPhCz, delivered a photoluminescence quantum yield of 84.5%, a full width at half maximum of 16nm in cyclohexane solution, and colour coordinates of (0.194, 0.739). In a phosphorescence-sensitised OLED the external quantum efficiency was 28.0%, and the TADF device reached CIE y 0.714 with a full width at half maximum of 25.8nm.
2. A green phosphor whose efficiency rose 1.6 times with added magnesium
Laser & Photonics Reviews · 09.11 · Chen Bai, School of Materials and Energy, Lanzhou University
Widening the colour gamut of LCD backlights and laser projectors needs narrow green phosphors. SrGa2S4:Eu2+ is well known for its narrow emission line, but low external quantum efficiency has kept it out of real use.
The team mixed in magnesium ions and raised external quantum efficiency from 33.1% to 53.1%. The interpretation is that magnesium stiffens the crystal lattice and cuts the energy lost to lattice vibration, supported by vibrational modes shifting in Raman spectroscopy.
The phosphor was put into LCD and laser projection prototypes, showing more vivid colour than the commonly used yellow YAG:Ce phosphor. The paper’s abstract, however, gives no colour gamut figures, and the comparison is presented at the level of screen images.
3. 532nm green and 20-micrometre pixels from cadmium-free quantum dots
ACS Applied Materials & Interfaces · 09.09 · Yuda Weng, China Jiliang University
Zinc selenium tellurium (ZnSeTe) quantum dots are a next-generation cadmium-free candidate. The problem is that the selenium and tellurium precursors react at very different rates, so tellurium does not enter the particle evenly, and colour purity and stability suffer as a result.
The team added sulphur as well to build a ZnSeTeS/ZnSe/ZnS alloy structure with a gradually changing composition, reducing lattice mismatch and defects. The green quantum dots are about 5.6nm in size, with a full width at half maximum of 33nm and an emission peak at 532nm, close to the BT.2020 green wavelength.
Changing the tellurium and sulphur ratios moves emission across 420 to 670nm. Combining thiol ligand exchange with ultraviolet exposure, the dots were patterned into 20×20×2.5-micrometre pixels, and the team names microdisplays for AR and VR as the application.
4. From blue to green with nanowire thickness alone
Applied Physics Letters · 09.08 · Qi Chen, Institute of Semiconductors, Chinese Academy of Sciences
In ultra-high-resolution displays pixels shrink below 1 micrometre, and at that size growing emitters of several colours together on one chip is difficult.
The team used selective area growth to stand n-GaN nanowires in an ordered array and coated them with InGaN/GaN multiple quantum wells and a p-GaN shell. Changing the size of the growth openings changes nanowire diameter, and diameter changes how much indium is incorporated.
As a result, a single growth run moved the emission wavelength continuously from blue to green. It did not reach red, and the abstract gives no device efficiency figures.
5. Carbon nanotube transistors built directly on a Micro-LED
ACS Applied Electronic Materials · 09.12 · Jian Hu, Hunan University
The smaller Micro-LED pixels get, the smaller the drive transistor must be and the closer it must sit to the LED. Usually LEDs are transferred onto a separately made drive substrate, and that transfer and bonding is a heavy burden on the process.
The team used the n-GaN layer of the Micro-LED as both the cathode and the buried gate of the transistor. With a p-type carbon nanotube thin-film transistor placed on top, the negatively biased n-GaN keeps the channel on through the insulating layer, giving a normally-on pixel.
Across 60 devices, compared with the conventional gate approach, subthreshold swing rose by 10.1% on average and threshold voltage shifted by 0.18V. Driving that switches off only the intersection receiving the scan signal was demonstrated in a 3×3 array, and the key point is that everything sits on one substrate with no transfer or bonding.
6. What set film uniformity in inkjet pixels was Marangoni flow
ACS Applied Materials & Interfaces · 09.10 · Youngwook Noh, Korea Institute of Industrial Technology
In an inkjet-printed emissive layer, the flow inside the droplet while it dries sets the shape of the film. The coffee ring, where the edge thickens, is relatively well understood, but Marangoni flow, driven by differences in surface tension, has been hard to handle.
The team controlled this flow by mixing three solvents and adding vacuum drying. Varying combinations of boiling point and surface tension, they divided the flow into four modes, and the predictions of a simple model built on Raoult’s law and the ideal gas law matched the actual pixel shapes.
Ink that flows outward and then reverses inward produced the most uniform emissive layer. Current efficiency and external quantum efficiency were 22 times higher than in devices without flow control.
7. A 3D display where a neural network picks the liquid crystal lens voltages
Optics Express · 09.09 · Yubo Liu, National Engineering Laboratory for TFT-LCD Materials and Technologies, Shanghai Jiao Tong University
A light field 3D display puts a lens array in front of the screen to send a different image in each viewing direction. With liquid crystal lenses, voltage can switch between 2D and 3D, but deciding what voltage to apply to each electrode to get the desired phase is tricky.
The team trained two neural networks on the relationship between electrode voltages, optical response and the depth information actually reconstructed. The networks output nine candidate voltage distributions with different Fresnel phase reset arrangements, and a choice is made among them on several criteria.
In their conclusion the team writes that the candidate with the best phase match did not necessarily give the best image. They obtained adjacent-view crosstalk of 7.22%, a luminance coefficient of variation of 0.91%, and a reconstructed depth of field of 46.875mm.
8. A liquid crystal network that turns white on contact with solvent
Nature Communications · 09.08 · Roshan Nasare, Tampere University
Energy-saving coatings and adaptive displays could use materials that switch between transparent and white. Existing approaches have had to change the structure substantially or create refractive index differences from outside, which kept the tuning range narrow.
In the liquid crystal network the team made, contact with polar protic solvents breaks hydrogen bonds, the phases separate on a nanometre scale, and those domains scatter visible light so the film turns white. In a 100-micrometre-thick film scattering efficiency exceeded 90%, with no fatigue on repetition.
Halogen-bond dopants and acid-base post-treatment can tune contrast and switching speed. But the switching trigger is solvent, not voltage, so the applications the team names are biological pattern recognition, underwater visibility and solvent discrimination.
9. Measuring composition inside a holographic grating at the nanometre scale
ACS Applied Materials & Interfaces · 09.09 · Yunfeng Hu, University of Colorado Boulder
Photopolymer holographic gratings are a material under discussion for holographic optical elements such as AR glasses. Performance is set by how periodically the material composition separates at the scale of the grating spacing, yet that has rarely been measured directly at that scale.
The team used AFM-IR, infrared spectroscopy with nanometre resolution, to map the composition of gratings recorded in a thiol-ene/polyurethane photopolymer. The concentration difference between peaks and troughs, averaged through the thickness, was about 1.7% g/g.
When they also measured diffraction while shaving the grating away layer by layer with a cryo-ultramicrotome, refractive index modulation and grating shape were not uniform through the thickness. The work offers a metrology framework for checking whether a recorded grating came out as designed.
10. An electrochromic transistor whose conductance is its colour
Advanced Optical Materials · 09.12 · Hang Liu, Southeast University and Nanjing University
This work aims to merge an image-recognising neural network device and a screen into one device. The team made an organic electrochemical transistor in which a single semiconducting polymer, P(g2T-TT), serves as both the switching channel and the colouring layer.
That way electrical conductance and visible colour are tied one to one. The best device held its state for more than 10,000 seconds after the voltage was cut, and conductance could be divided into 120 levels.
An artificial neural network built from these devices recognised handwritten digits with 96.1% accuracy. Using colour states as a physical filter to improve classification of noisy images is what the paper presents as new.
11. A flexible white AC electroluminescent device made by screen printing
ACS Applied Electronic Materials · 09.10 · Yifan Tang, Beijing Institute of Graphic Communication
Alternating-current electroluminescent (ACEL) devices are a simple structure, phosphor powder between dielectric layers lit by AC, so patterning them by printing is easy. The challenge has been a printable layer that is transparent and has good dielectric performance.
The team made a UV-curable transparent dielectric ink. The printed layer had transmittance above 90% relative to ITO-PET over 400 to 700nm and a relative permittivity of about 25 at 1kHz. A single emissive layer mixing ZnS:Cu and CaAlSiN3:Eu2+ at 3:1 gave white light at colour coordinates of (0.331, 0.331).
Luminance was 48.7 cd/m² at 120V and 500Hz, with luminous efficacy of 10.4 lm/W. After 1,000 bends at a 5mm radius about 77% of initial luminance remained. The figures point more towards patterned lighting than screens.
12. A flexible stress hormone sensor made from IGZO, a display backplane material
Advanced Electronic Materials · 09.09 · Ngoc Thanh Ho, Griffith University
The amorphous oxide semiconductor IGZO is a mainstay material of display backplanes. This paper built the same material at wafer scale on a polyimide substrate and used it as a wearable sensor measuring cortisol, a stress hormone.
Across 50 devices the average transconductance of 0.326mS and subthreshold swing of 130.75mV/dec came out uniform, and characteristics held when bent to a radius of 15 to 30mm or deformed 100 times. Large-area uniformity, the strength of backplane processing, carried over directly into value for the sensor.
After immobilising an aptamer that binds only to cortisol, current changed with concentration from 10fM to 10µM, and controls using a scrambled-sequence aptamer and other substances confirmed that it responds only to cortisol.