Efficient hole-transporting materials (HTMs) are crucial for improving the power conversion efficiency (PCE) and operational stability of perovskite solar cells (PSCs). Nevertheless, the rational design of organic HTMs that simultaneously combine suitable energy-level alignment, visible transparency, good chemical stability, facile film formation, and efficient hole-transport characteristics remains a major challenge. In this work, first-principles calculations were employed to investigate the structural, optical, electrochemical, solubility, chemical stability, and charge-transport properties of five spirofluorenedithiolane-based derivatives (SFT1-SFT5), designed through thiophene-bridged end-capped acceptor engineering of the parent SFT-STPA molecule. The designed HTMs exhibit suitable frontier orbital alignment with the perovskite absorber, indicating favorable hole extraction and transport. Their highest occupied molecular orbitals (HOMO) energies range from - 5.15 to -5.26 eV, indicating improved stabilization relative to the reference molecule (-5.07 eV). Moreover, the designed derivatives retain absorption maxima below 470 nm, which helps minimize parasitic absorption and preserve effective light harvesting by the perovskite layer. Reduced reorganization energies (0.3032-0.3933 eV), higher hole-transfer integrals (0.1250-0.1690 eV), and rapid hole-transfer rates collectively indicate favorable hole-transport behavior. In addition, more favorable solvation free energies (-56.84 to -47.92 kcal mol- 1) suggest improved processability and film-forming ability. Overall, these results identify spirofluorenedithiolane-based derivatives as promising HTM candidates for high-performance PSCs.
Conventional laser trepanning drilling (LTD) often produces microholes with excessive taper, high surface roughness, and thick recast layers, severely limiting its application in precision manufacturing. To address these limitations, this study proposes and systematically investigates ultrasonic vibration-assisted laser trepanning drilling (UVLTD). A combined experimental and multi-physics numerical approach is employed to elucidate the mechanisms by which ultrasonic vibration controls hole geometry and surface quality. Results obtained using 304 stainless steel as the substrate demonstrate that ultrasonic vibration induces periodic fluid disturbances and flow reversal within the molten pool, thereby significantly enhancing convective heat transfer and melt expulsion. This is evidenced by an 18 % increase in melt flow velocity and volumetric forces reaching 1.2 × 109 N/m3, which collectively suppress bottom overheating and resolidification. Compared to conventional LTD, UVLTD reduces hole taper by 12.1 %, surface roughness by 67 %, and recast layer thickness by 43.5 %. The developed numerical model demonstrates high accuracy, predicting hole geometry with errors of less than 10 %. Furthermore, comprehensive parametric studies confirm that UVLTD consistently yields larger hole diameters and smaller taper angles than LTD across a wide range of processing conditions, with the most pronounced advantages observed at high pulse frequencies and trepanning speeds. This work provides both a fundamental understanding and experimental validation of UVLTD as an effective strategy for high-quality microhole fabrication in precision manufacturing.
Traumatic macular holes (TMH) represent a distinct subset of macular holes arising from ocular trauma. This review examines controversies in TMH management: whether and when to operate, how to interpret OCT biomarkers as prognostic guides, special considerations in the pediatric population, and the role of emerging surgical and pharmacologic alternatives. Minimum hole diameter and the presence of intraretinal cysts appears to reliably stratify eyes by likelihood of spontaneous closure. Pediatric TMH generally demonstrates high spontaneous closure rates. Vitrectomy with ILM peeling achieves high anatomical closure rates; while earlier surgery has been associated with better visual outcomes in observational data, this association is likely confounded by the tendency to observe longer in eyes with more extensive comorbidities and poorer baseline prognosis. Topical treatment is an option, and adjuvant maneuvers and plugging material can be considered during vitrectomy for refractory or TMHs at high risk for nonclosure. The association between earlier surgery and better visual outcomes in the literature requires careful interpretation due to case-mix confounding. A systematic, optical coherence tomography-guided approach integrating hole characteristics, patient age, and associated ocular injuries allows individualized management of TMH. Continued refinement of surgical techniques is promising for large and refractory holes.
Tailored self-assembled hole-transporting materials (SA-HTMs) have been shown to be an effective approach to enhance the performance of inverted perovskite solar cells (PSCs). Based on a π-conjugation engineering strategy, we use Ph-4PACz as the molecular backbone and design three novel SA-HTMs (PACNT, PACDC, and PACFT) by introducing naphthyl, acenaphthyl, and anthryl groups, respectively. By combining density functional theory (DFT), time-dependent DFT (TD-DFT), and molecular dynamics (MD) simulations, the effects of conjugated extension on molecular optoelectronic properties, hole transport, and interfacial behavior were systematically investigated. Theoretical results indicate that the introduction of conjugated groups significantly enhances the molecular dipole moment (reaching 3.18 D for PACFT), optimizes energy level alignment, and increases the magnitude of interfacial adsorption energy (-2.11 eV for PACFT). PACFT exhibits the lowest hole reorganization energy (0.163 eV) and the highest hole mobility (1.74 × 10-1 cm2 V-1 s-1), representing an improvement of four orders of magnitude compared to Ph-4PACz, while effectively passivating surface defects on the perovskite. This work demonstrates that extending π-conjugation is an effective strategy for synergistically enhancing the hole transport capability and interfacial stability of SA-HTMs.
To quantify early real-world visual acuity (VA) responder rates at 25-35 days after idiopathic full-thickness macular hole (FTMH) surgery and evaluate the influence of hole size, gas tamponade, and prescribed duration of face-down positioning. In this retrospective cohort study, 193 eyes were analyzed after pars plana vitrectomy with internal limiting membrane peeling and SF6 20% or C3F8 12% gas tamponade. Routine Snellen (decimal) best-corrected VA was extracted from the medical record and converted to logarithm of the minimum angle of resolution (logMAR). Primary outcomes were mean VA change from the last preoperative assessment to the postoperative visit at 25-35 days and rates of two and three lines VA improvement (≥ 0.2 and ≥ 0.3 logMAR, respectively). Secondary outcomes were baseline-adjusted postoperative VA and anatomical closure. Overall, 66.8% of eyes improved by ≥ 0.2 logMAR and 52.3% by ≥ 0.3 logMAR. Mean VA improved from 0.774 ± 0.409 to 0.455 ± 0.346 logMAR (mean VA change - 0.318 logMAR; p < 0.001). VA change and responder rates did not differ significantly across International Vitreomacular Traction Study size groups (< 250 μm, 250-400 μm, > 400 μm), and no statistically significant association with gas choice or prescribed face-down positioning duration was detected within the limitations of this retrospective cohort. Baseline-adjusted postoperative VA differed by size, with large holes having worse early postoperative VA than small and medium holes, independent of prescribed face-down positioning duration or vitreomacular traction status. Anatomical closure differed by International Vitreomacular Traction Study size group (small 98.9%, medium 96.7%, large 78.0%; p < 0.001). In routine care, FTMH surgery results in clinically meaningful early VA improvement at 25-35 days, with approximately two-thirds of eyes gaining ≥ 0.2 logMAR and half gaining ≥ 0.3 logMAR. Although VA improvement was similar across size groups, large holes had lower closure rates and worse early postoperative BCVA. No statistically significant association between gas choice, prescribed face-down positioning duration, and the extent of VA improvement was detected in this retrospective cohort.
Spin qubits are typically operated in the lowest orbital of a quantum dot to minimize interference from nearby states. In valence-band hole systems, strong spin-orbit coupling links spin and orbital degrees of freedom, strongly influencing the hole g-factor, a key parameter for qubit control. We investigate the out-of-plane g-factor in Ge quantum dots using excitation (single-particle) and addition (many-body) spectra. Excitation spectra allow us to distinguish the pure Zeeman g-factor from orbital contributions to the magnetic field splitting of states despite the strong spin-orbit coupling. This distinction clarifies discrepancies between g-factors extracted with the two methods, for different orbital states and different hole numbers. Furthermore, we find gate-tunability of g-factors at the level of 15%, highlighting its relevance for all-electric qubit manipulation.
To report two cases of macular holes (MHs) that spontaneously formed and closed following pars plana vitrectomy (PPV) and summarize the literature. A 72-year-old man and a 67-year-old woman underwent PPV for repair of rhegmatogenous retinal detachment. Both patients developed MHs following PPV. In both cases, the holes closed without further surgical intervention. A retrospective chart review and literature review were conducted to supplement this study. Spontaneous MH closure is possible in post-vitrectomized eyes. Small- or medium-sized MHs ( < 400 µm) may be more likely to close spontaneously. Large MHs ( > 400 µm) that form in the setting of vitreomacular traction (VMT) from residual posterior vitreous cortex remnants were found to close after spontaneous VMT release, often within the first month following surgery. Overall, among eyes with spontaneous closure, about two-thirds of MHs in the literature closed spontaneously within the first month following diagnosis, and 4 in 5 holes closed within 3 months. Over one-third of MHs that close spontaneously reopen later, some requiring additional surgery to achieve closure. Sustained closure was seen in this report up to 7 years following closure.
Chalcogen bonding (ChB), an attractive noncovalent σ-hole interaction involving Group 16 elements, has recently emerged as a powerful activation mode in synthetic chemistry. This review provides a comprehensive overview of the burgeoning field of ChB enabled radical reactions, highlighting how these σ-hole interactions unlock unprecedented reactivities under mild, transition metal-free, and photocatalyst-free conditions. The discussion is structured around two principal mechanistic themes. The first section examines cationic ChB-enabled processes, wherein sulfonium and selenonium salts act as potent σ-hole donors to form photoactive charge-transfer complexes with Lewis bases or dichalcogenides. The second section explores neutral ChB-enabled radical reactions. Detailed mechanistic insights from spectroscopic, computational, and radical-trapping experiments underscore the critical role of ChB in orchestrating single-electron transfer. By consolidating these advances, this review illuminates the capabilities of chalcogen bonding as a tunable and versatile platform for radical generation and aims to inspire future developments in asymmetric catalysis, multicatalytic networks, and continuous-flow applications.
To compare the functional and anatomical outcomes of the inverted internal limiting membrane (ILM) flap covering and stuffed techniques in primary macular hole (MH) surgery. This retrospective case series included 57 eyes that underwent inverted ILM flap surgery by a single surgeon (covering, n = 33; stuffed, n = 24). Best-corrected visual acuity (BCVA) and optical coherence tomography findings, including restoration of the external limiting membrane (ELM) and ellipsoid zone (EZ), were assessed preoperatively and at 1 and 6 months postoperatively. There were no significant differences in preoperative characteristics or MH closure rates between groups. BCVA improved significantly in both groups postoperatively; however, BCVA was significantly better in the covering group at 1 month (P = 0.005) and 6 months (P = 0.001). Restoration of the ELM and EZ was more frequent in the covering group at 1 month (ELM, P < 0.001; EZ, P = 0.002) and 6 months (ELM, P < 0.001; EZ, P = 0.001). Although both techniques achieved comparable anatomical closure, the covering method provided superior visual and outer retinal recovery for a wide range of macular holes, including medium-to-large cases. These findings suggest that the covering technique may be preferable as a standard approach for primary MH surgery.
Rotational spectroscopy reveals that fluorination switches CO-arene interactions to a nonclassical lp⋯π-hole binding motif. CO binds perpendicularly to perfluorinated aromatics, with C ← O bond contraction analogous to metal carbonyls, highlighting how π-hole interactions control ligand behaviour in weakly bound systems.
Physics-based charge transport modelling is widely used to analyse multilayer optoelectronic devices. However, conventional drift-diffusion discretisation schemes can exhibit numerical instability at heterojunction interfaces with abrupt discontinuities in energy levels and doping density. In quantum-dot light-emitting diodes (QD-LEDs), the heterojunction between the hole injection layer (HIL) and the hole transport layer (HTL) represents such a critical interface. In this study, a field-dependent current density scheme is proposed to stabilise the discretisation of drift-diffusion currents across heterojunction interfaces. By incorporating the local electric-field direction when evaluating carrier densities at discretised boundaries, the scheme suppresses numerical artefacts associated with mean-value interpolation of the carrier density. The stability and convergence of our model are examined using a one-dimensional finite-difference framework and subsequently implemented in a charge transport model for QD-LEDs. Using this model, the effects of energy-level alignment and acceptor doping density at the HIL/HTL interface on charge transport and electro-optical characteristics are analysed. The simulations reproduce typical voltage-dependent experimental trends in current density, luminance, and external quantum efficiency, providing insight into the role of the HIL/HTL heterojunction in carrier injection. Owing to its numerical formulation, the proposed approach is applicable to a broad range of multilayer semiconductor devices involving heterojunction interfaces.
We fabricated an all-inorganic self-powered photodetector based on ZnO/AgBiS2/PbS-EDT. Compared with the reference device employing spiro-OMeTAD as the hole transport layer (HTL), the PbS-EDT HTL has higher stability, electrical conductivity and favourable near-infrared light absorption. Consequently, the as-fabricated photodetector exhibits superior photovoltaic performance, stability and photoresponsivity over the reference device.
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To describe and evaluate an ophthalmic viscosurgical device (OVD)-assisted press injection technique for stabilizing a sectorial inverted internal limiting membrane (ILM) flap in full-thickness macular hole (MH) surgery without perfluorocarbon liquid or endotamponade. Twenty-eight eyes (28 patients) with full-thickness MH underwent 27-gauge pars plana vitrectomy with a superior sectorial inverted ILM flap. An OVD was first placed over the MH before indocyanine green (ICG) staining to minimize direct dye exposure to the fovea. After ILM flap creation, gentle OVD press injection was performed to flatten and secure the inverted flap over the hole. Postoperative outcomes included best-corrected visual acuity (BCVA), macular hole closure on optical coherence tomography (OCT), and surgical complications. All surgeries were completed successfully using the OVD-assisted press injection technique. Anatomical closure of the macular hole was achieved in all eyes (100%). OCT demonstrated stable ILM flap coverage throughout follow-up. Mean BCVA improved significantly from 0.92 ± 0.29 log MAR preoperatively to 0.60 ± 0.29 log MAR at 3 months postoperatively (P < 0.001). No retinal detachment, MH reopening, or clinical evidence of ICG-related toxicity occurred. Intraocular pressure remained stable; transient hypotony occurred in two eyes and resolved within 1 week. OVD-assisted press injection provides reliable mechanical stabilization of the inverted flap and enables macular hole closure without the need for perfluorocarbon liquids or endotamponade. Not applicable.
We investigate the formation and characteristics of electron and hole polarons in the ferroelectric material PbTiO3 using a first-principles-based supercell approach and electron-phonon coupling calculations. We find that holes form two-dimensional large polarons spread across oxygen sites, driven by relatively weak hole-phonon coupling. In contrast, electrons experience stronger coupling with phonons and localize as small polarons on Ti sites. Spin-orbit coupling (SOC) has a negligible effect on hole polaron formation but significantly promotes the delocalization of electron polarons. These results provide fundamental insight into polaron physics in ferroelectric perovskites and suggest potential implications for carrier transport and separation in ferroelectric-based materials and devices.
Filtration methods are widely used for microplastic (MP) isolation, yet filter membrane selection can introduce substantial bias into MP quantification. In this study, five types of membranes, classified as single-layer-hole [polycarbonate track-etched (PCTE)], multilayer-fiber [polytetrafluoroethylene (PTFE) and glass fiber (GF)], and multilayer-hole [mixed cellulose esters (MCE) and nylon (NY)], were systematically compared for MP quantification. Particle abundance was quantified by scanning electron microscopy (SEM)-based visual counting on membranes. Polystyrene (PS) microspheres exhibited superior dispersion on single-layer-hole (PCTE) and multilayer-fiber (PTFE) membranes. However, partial particle embedding occurred in multilayer-fiber membranes (PTFE and GF), whereas pronounced aggregation occurred on multilayer-hole membranes (MCE and NY). Accordingly, PCTE exhibited the most stable quantification performance across PS concentrations and pH conditions, with RSD values of 3.05-17.68%. Application to bottled drinks further showed that PCTE improved the differentiation of particle abundance among brands. LDIR analysis indicated that the collected particles from bottled drinks consisted of both MPs, mainly polyethylene terephthalate, polyethylene, polybutadiene rubber, and polyvinyl chloride, as well as non-MPs (54.50% - 81.29%). Overall, selection of appropriate membranes is critical for MP quantification, and single-layer-hole PCTE membranes are recommended for reliable visual counting and improved comparability across studies.
Few studies have demonstrated the reliability of biodegradable osteosynthesis systems in orthognathic surgery; however, studies on the use of biodegradable osteosynthesis systems after mandibular osteotomy, including sagittal split ramus osteotomy (SSRO), are limited. This pilot study aimed to compare the safety and skeletal stability after segmental fixation using curved titanium and box-type biodegradable systems in SSRO for mandibular prognathism. Patients who underwent SSRO for correction of mandibular protrusion with malocclusion between September 2024 and March 2025 were included. After conventional SSRO, the bilateral segments were fixed using curved 6-hole titanium plates (Ti group) or 6-hole box-type biodegradable plates (Bi group). Lateral and frontal cephalograms and computed tomography images were obtained before (T0), 5±2 days after (T1), and 6±1 months after surgery (T2). In the Ti group, although the absolute change in the ramus plane and gonial angles from T1 to T2 was -2.3±5.1 and 3.6±7.4 degrees, respectively, no significant change was observed in any of the measured angles. In contrast, in the Bi group, significant changes from T1 to T2 were observed in the mandibular plane (4.8±2.3 degrees), ramus plane (-5.7±4.0 degrees), and gonial angles (8.8±4.2 degrees). The changes in the vertical and horizontal positions of point B, menton and pogonion were not significantly different between the 2 groups. The results of this pilot study with a small sample size suggested that in patients undergoing SSRO, bone segmental fixation using 6-hole box-type biodegradable plates may provide acceptable short-term skeletal stability and safety. Since definitive comparisons require larger prospective studies, further prospective studies with larger sample sizes are warranted.
Recent advances in photovoltaic technologies have established lead halide perovskites as benchmark materials for optoelectronic applications, but serious concerns persist regarding the toxicity of lead, their principal constituent element. In this context, bismuth-based perovskite-inspired materials have emerged as a promising lead-free alternative, offering comparable electronic characteristics. Here, we explore the structural, electronic and transport properties of Cs3Bi2I9 and Cs3Bi2Br9, two perovskite-inspired materials with significant potential for photovoltaic and photocatalytic applications. With state-of-the-art first-principles calculations, we investigate the subtle effects of iodine/bromine (I/Br) mixing on the materials' physico-chemical properties. We predict a change in phase stabilities around 40% Br content: below 30% Br, the iodine-dominant P63/mmc phase is stable, while beyond 40% Br, the bromine-dominant P-3m1 phase becomes energetically favorable, consistent with experimental observations. The electronic bandgap increases with Br content, and effective mass calculations indicate that electrons exhibit lower effective masses and higher mobility compared to holes, with hole localization intensifying as the Br content increases. Overall, our findings underscore the critical role of halogen composition in modulating the structural, electronic, and transport properties of these materials, providing valuable insights for optimizing halide contents in perovskite-inspired systems for next-generation optoelectronic applications.