Centimetre-scale perovskite solar cells with fill factors of more than 86 per cent.

Owing to rapid development in their efficiency1 and stability2, perovskite solar cells are at the forefront of emerging photovoltaic technologies. State-of-the-art cells exhibit voltage losses3-8 approaching the theoretical minimum and near-unity internal quantum efficiency9-13, but conversion efficiencies are limited by the fill factor (<83%, below the Shockley-Queisser limit of approximately 90%). This limitation results from non-ideal charge transport between the perovskite absorber and the cell's electrodes5,8,13-16. Reducing the electrical series resistance of charge transport layers is therefore crucial for improving efficiency. Here we introduce a reverse-doping process to fabricate nitrogen-doped titanium oxide electron transport layers with outstanding charge transport performance. By incorporating this charge transport material into perovskite solar cells, we demonstrate 1-cm2 cells with fill factors of >86%, and an average fill factor of 85.3%. We also report a certified steady-state efficiency of 22.6% for a 1-cm2 cell (23.33% ± 0.58% from a reverse current-voltage scan).

Modified Radical Neck Dissection for Papillary Thyroid Carcinoma via a Combined Endoscopy Approach: The Transoral Approach and the Chest Approach.

BACKGROUND: Recently, modified radical neck dissection (MRND) for papillary thyroid carcinoma (PTC) has been performed by the transoral endoscopic approach.1 However, dissection of level II lymph nodes using only the transoral approach is highly difficult because of the inadequate axis of surgical view. Hence, we decided to combine the transoral and chest approaches to perform MRND. To the best of our knowledge, this is the first video case of MRND using the combined approach. PATIENT AND METHODS: A 35-year-old woman was diagnosed with cT1aN1bM0 right PTC (metastatic to right level III lymph nodes). The patient underwent total thyroidectomy, bilateral central neck dissection (CND), and right MRND via a combined endoscopic approach: the transoral and chest approaches. Total thyroidectomy and bilateral central neck dissection were performed via the transoral approach, similar to prior studies.2-6 The chest approach can help the surgeon to perform level II and the transoral approach was used to dissect the lymph node of levels III and IV. RESULTS: The total time for total thyroidectomy, bilateral CND, and right MRND was 190 min. The time for MRND was 90 min. The number of harvested lymph nodes were 14 in the right lateral compartments, and the number of metastatic lymph nodes were 2 in the lateral compartments. There were no major postoperative complications. The patient was completely satisfied with the cosmetic result. CONCLUSIONS: The combined approach of the transoral and chest approaches was sufficient to perform total thyroidectomy and MRND for levels II, III, and IV.

Transoral endoscopic thyroidectomy vestibular approach versus conventional open thyroidectomy for the treatment of benign thyroid tumours: A prospective cohort study.

INTRODUCTION: Thyroid tumours are a common condition and open surgery is a conventional method for treating benign thyroid tumours when surgery is indicated. In this study, we evaluate the outcomes of benign thyroid tumour treatment using transoral endoscopic thyroidectomy via vestibular approach (TOETVA) and compare the results with those of conventional open thyroidectomy (COT). PATIENTS AND METHODS: We conducted a prospective cohort study between 100 patients who underwent TOETVA and 100 who underwent COT surgery for benign diseases from June 2018 to December 2021 in our hospital. Outcomes between the two groups, including post-operative complications, operative time and length of stay, were compared. RESULTS: The surgical time in the TOETVA group was significantly longer than in the COT group. The operative time of lobectomy in the TOETVA and COT groups was 77.5 ± 13.3 and 51.5 ± 4.2 min, respectively, with a P < 0.001. The operative time of total thyroidectomy in the TOETVA and COT groups was 108.1 ± 7.0 and 65.0 ± 4.1 min, respectively, with a P < 0.001. There was no difference in post-operative length of stay between the two groups. In TOETVA group, there were no patients who converted to open surgery. Amongst all 200 patients in the study, there were no cases of post-operative bleeding. The transient hypoparathyroidism rate after surgery in the TOETVA and COT groups was 3% and 2%, respectively, with no statistically significant difference (P = 0.651). Similarly, the transient recurrent laryngeal nerve injury rate showed no difference between the two groups, with rates of 5% and 4% in the TOETVA and COT groups, respectively (P = 0.733). There were no cases of post-operative infection in either group in our study. At 3 months postoperatively, the cosmetic satisfaction were significantly higher in the endoscopic groups than in the conventional group (P < 0.001). CONCLUSIONS: TOETVA is a safe and effective method, with a low complication rate and optimal aesthetic results compared to traditional surgery to treat benign thyroid tumours.

Understanding the Role of (W, Mo, Sb) Dopants in the Catalyst Evolution and Activity Enhancement of Co3 O4 during Water Electrolysis via In Situ Spectroelectrochemical Techniques.

Unlocking the potential of the hydrogen economy is dependent on achieving green hydrogen (H2 ) production at competitive costs. Engineering highly active and durable catalysts for both oxygen and hydrogen evolution reactions (OER and HER) from earth-abundant elements is key to decreasing costs of electrolysis, a carbon-free route for H2 production. Here, a scalable strategy to prepare doped cobalt oxide (Co3 O4 ) electrocatalysts with ultralow loading, disclosing the role of tungsten (W), molybdenum (Mo), and antimony (Sb) dopants in enhancing OER/HER activity in alkaline conditions, is reported. In situ Raman and X-ray absorption spectroscopies, and electrochemical measurements demonstrate that the dopants do not alter the reaction mechanisms but increase the bulk conductivity and density of redox active sites. As a result, the W-doped Co3 O4 electrode requires ≈390 and ≈560 mV overpotentials to reach ±10 and ±100 mA cm-2 for OER and HER, respectively, over long-term electrolysis. Furthermore, optimal Mo-doping leads to the highest OER and HER activities of 8524 and 634 A g-1 at overpotentials of 0.67 and 0.45 V, respectively. These novel insights provide directions for the effective engineering of Co3 O4 as a low-cost material for green hydrogen electrocatalysis at large scales.

Three-Port Transoral Robotic Thyroidectomy in Papillary Thyroid Carcinoma.

BACKGROUND: Although transoral thyroidectomy has become popular in thyroid surgery, transoral robotic thyroidectomy (TORT) has only been successfully applied in a very small number of medical centers worldwide.[1,2,3,4,5] In this video, we show a three-port TORT without an axillary incision for papillary thyroid carcinoma. PATIENT AND METHODS: A 35-year-old female with cT1aN0M0 papillary thyroid carcinoma had a strong motivation to proceed with surgery but avoid external neck incisions. Thus, we decided to perform a hemithyroidectomy with isthmusectomy using a transoral robotic approach, employing the da Vinci Xi surgical system. RESULTS: The operation was completed successfully without conversion to open surgery. The working space creation time, docking time, and console time were 30 min, 40 min, and 130 min, respectively. The pathological results were papillary thyroid carcinoma with 6- and 5-mm tumors. The patient was discharged 4 days after surgery without any complications such as bleeding, infection, mental nerve damage, permanent hoarseness, or hypoparathyroidism. The patient was completely satisfied with the cosmetic result. CONCLUSION: Three-port TORT without an axillary incision is a promising approach with optimal cosmetic outcomes. For Vietnam, a developing country, success in the application of TORT using the new da Vinci Xi robotic platform for thyroid cancer is an important milestone in the development of thyroid surgery.

Bilateral Central Neck Dissection via Transoral Approach in Papillary Thyroid Carcinoma.

BACKGROUND: The transoral endoscopic vestibular approach (TOETVA) for thyroidectomy is gaining popularity (Russell et al. in Thyroid 28(7):825-829, 2018; Le et al. in Surg Laparosc Endosc Percutan Tech 30(3):209-213, 2020; Liao et al. in Laryngoscope 130(6):1603-1608, 2020). TOETVA has been utilized successfully in performing thyroidectomy, parathyroidectomy, and neck dissection, via both endoscopic and robotic techniques (Razavi et al. in Head Neck 40(10):2246-2253, 2018; Otolaryngol Head Neck Surg 159(4):625-629, 2018; Ngo et al. in J ENT, 2020. https://doi.org/10.1177/0145561320943358 ; Ann Surg Oncol 28(5):2766, 2021). In this video, we show bilateral central neck dissection via transoral approach in papillary thyroid carcinoma. PATIENT AND METHODS: A 37-year-old female with no significant medical history was diagnosed pT3bN0M0 intraoperatively with the tumor having slightly invaded the strap muscle. Thus, we decided to perform total thyroidectomy with bilateral central neck dissection via transoral approach. METHODS: Prelaryngeal dissection: in the prelaryngeal compartment, soft tissue containing these lymph nodes was intimately associated with the pyramidal lobe. Right paratracheal dissection: fibrofatty tissue was dissected off the prevertebral fascia and the trachea with preservation of right parathyroid glands. Pretracheal lymph nodes were removed with paratracheal dissection. Left paratracheal dissection: the lymphatic tissue was then dissected off the prevertebral and esophageal musculature and the trachea after identifying the left parathyroid glands. Finally, bilateral central neck dissection was finished with preservation of the nerve and parathyroid glands. RESULTS: The operation was completed successfully without conversion to open surgery. The operative time for central neck dissection was 20 min. There were nine harvested lymph nodes in the central compartments, while there were two metastatic lymph nodes of papillary thyroid carcinoma with 3 × 3 mm maximal dimension. There were no major postoperative complications. CONCLUSION: Central neck dissection via TOETVA is a safe and feasible method in selected patients.

Transoral Endoscopic Modified Radical Neck Dissection for Papillary Thyroid Carcinoma.

BACKGROUND: Recently, transoral endoscopic thyroidectomy via the vestibular approach (TOETVA) has become popular worldwide.1-3 After controlling for the technique, the authors used the transoral endoscopic approach to modified radical neck dissection (MRND) for papillary thyroid carcinoma with clinically positive lymph nodes in the lateral compartments. To the best of their knowledge, the authors report the first case of TOETVA for MRND. PATIENT: A 27-year-old woman had a diagnosis of cT1aN1bM0 right papillary thyroid carcinoma (metastatic to a small right level 4 lymph node). Therefore, total thyroidectomy, bilateral central neck dissection, and MRND of right levels 2, 3, and 4 were performed via the transoral endoscopic approach. METHODS: Total thyroidectomy and bilateral central lymph node dissections were performed based on the three-trocar Anuwong technique.4 Then, the fourth incision was made near the sixth teeth in the right oral vestibular area for insertion of the fourth 5-mm trocar, which was used to expose the lateral lymph compartment and to perform right MRND easily. RESULTS: The operation was completed successfully without conversion to open surgery. The total operative time was 170 min, and the operating time for MRND was 55 min. The numbers of harvested lymph nodes were 7 and 8 in the central and right lateral compartments, respectively. The numbers of metastatic lymph nodes were 2 and 1 in the central and lateral compartments, respectively. No major postoperative complications occurred. CONCLUSION: Transoral endoscopic MRND of levels 2, 3, and 4 can be feasible and safe for highly selected patients.

In Situ Formation of Mixed-Dimensional Surface Passivation Layers in Perovskite Solar Cells with Dual-Isomer Alkylammonium Cations.

Dimensional engineering of perovskite solar cells has attracted significant research attention recently because of the potential to improve both device performance and stability. Here, a novel 2D passivation scheme for 3D perovskite solar cells is demonstrated using a mixed cation composition of 2D perovskite based on two different isomers of butylammonium iodide. The dual-cation 2D perovskite outperforms its single cation 2D counterparts in surface passivation quality, resulting in devices with an impressive open-circuit voltage of 1.21 V for a perovskite composition with an optical bandgap of ≈1.6 eV, and a champion efficiency of 23.27%. Using a combination of surface elemental analysis and valence electron spectra decomposition, it is shown that an in situ interaction between the 2D perovskite precursor and the 3D active layer results in surface intermixing of 3D and 2D perovskite phases, providing an effective combination of defect passivation and enhanced charge transfer, despite the semi-insulating nature of the 2D perovskite phase. The demonstration of the synergistic interaction of multiple organic spacer cations in a 2D passivation layer offers new opportunities for further enhancement of device performance with mixed dimensional perovskite solar cells.

96X Screen-Printed Gold Electrode Platform to Evaluate Electroactive Polymers as Marine Antifouling Coatings.

Several alternatives are currently investigated to prevent and control the natural process of colonization of any seawater submerged surfaces by marine organisms. Since few years we develop an approach based on addressable electroactive coatings containing conducting polymers or polymers with lateral redox groups. In this article we describe the use of a screen-printed plate formed by 96 three-electrode electrochemical cells to assess the potential of these electroactive coatings to prevent the adhesion of marine bacteria. This novel platform is intended to control and record the redox properties of the electroactive coating in each well during the bioassay (15 h) and to allow screening its antiadhesion activity with enough replicates to support significant conclusions. Validation of this platform was carried out with poly(ethylenedioxythiophene) (PEDOT) as electroactive coating obtained by electropolymerization of EDOT monomer in artificial seawater electrolyte on the working electrode of each electrochemical cell of the 96-well microplate.

Bacterial anti-adhesion activity based on the electrochemical properties of polymethacrylates bearing ferrocenyl pendant groups.

Much current research is focused on preventing and controlling the natural process of colonization by marine organisms of surfaces submerged in seawater. Previously, the authors' laboratory has reported the synthesis and the full physico-chemical characterization of homopolymers obtained from 1-ferrocenylmethyl methacrylate (FMMA), 2-(ferrocenylmethoxy)ethyl methacrylate (FMOEMA), and 3-(ferrocenylmethoxy)propyl methacrylate (FMOPMA). Here, the bacterial anti-adhesion activity of these homopolymers (pFMMA, pFMOEMA and pFMOPMA) is reported when stimulated in 96-well microplates containing a printed electrochemical cell in each well. Polymers were deposited on the printed carbon working electrode of each well in two columns each comprising eight wells. Their electrochemical anti-adhesion properties were evaluated by inoculating a marine biofilm forming bacterial strain, Pseudoalteramonas lipolytica, in each well and then applying recurrent scans for 15 h. The results revealed an intrinsic anti-adhesion activity of all the polymers. This activity was amplified by a factor of 10 when potential recurrent scans were applied.

Flame-made ultra-porous TiO2 layers for perovskite solar cells.

We report methyl ammonium lead iodide (MAPbI3) solar cells with an ultra-porous TiO2 electron transport layer fabricated using sequential flame aerosol and atomic layer depositions of porous and compact TiO2 layers. Flame aerosol pyrolysis allows rapid deposition of nanostructured and ultra-porous TiO2 layers that could be easily scaled-up for high-throughput low-cost industrial solar cell production. An efficiency of 13.7% was achieved with a flame-made nanostructured and ultra-porous TiO2 electrode that was coated with a compact 2 nm TiO2 layer. This demonstrates that MAPbI3 solar cells with a flame-made porous TiO2 layer can have a comparable efficiency to that of the control MAPbI3 solar cell with the well-established spin-coated porous TiO2 layer. The combination of flame aerosol and atomic layer deposition provides precise control of the TiO2 porosity. Notably, the porosity of the as-deposited flame-made TiO2 layers was 97% which was then fine-tuned down to 87%, 56% and 35% by varying the thickness of the subsequent compact TiO2 coating step. The effects of the decrease in porosity on the device performance are discussed. It is also shown that MAPbI3 easily infiltrates into the flame-made porous TiO2 nanostructure thanks to their high porosity and large pore size.

Photoluminescence study of time- and spatial-dependent light induced trap de-activation in CH3NH3PbI3 perovskite films.

Organometal halide perovskite-based solar cells have rapidly achieved high efficiency in recent years. However, many fundamental recombination mechanisms underlying the excellent performance are still not well understood. Here we apply confocal photoluminescence microscopy to investigate the time and spatial characteristics of light-induced trap de-activation in CH3NH3PbI3 perovskite films. Trap de-activation is characterized by a dramatic increase in PL emission during continuous laser illumination accompanied by a lateral expansion of the PL enhancement far beyond the laser spot. These observations are attributed to an oxygen-assisted trap de-activation process associated with carrier diffusion. To model this effect, we add a trap de-activation term to the standard semiconductor carrier recombination and diffusion models. With this approach we are able to reproduce the observed temporal and spatial dependence of laser induced PL enhancement using realistic physical parameters. Furthermore, we experimentally investigate the role of trap diffusion in this process, and demonstrate that the trap de-activation is not permanent, with the traps appearing again once the illumination is turned off. This study provides new insights into recombination and trap dynamics in perovskite films that could offer a better understanding of perovskite solar cell performance.

Danger in the Dark: Stability of Perovskite Solar Cells with Varied Stoichiometries and Morphologies Stressed at Various Conditions.

The long-term stability of perovskite solar cells (PSCs) remains a bottleneck for commercialization. While studies on the stoichiometry and morphology of PSCs with regard to performance are prevalent, understanding the influence of these factors on their long-term stability is lacking. In this work, we evaluate the impact of stoichiometry and morphology on the long-term stability of cesium formamidinium-based PSCs. We demonstrate that the lead iodide (PbI2) to formamidinium iodide (FAI) ratio influences stability under various stress factors (elevated temperature and light). A high molar ratio (PbI2/FAI > 1.1) in the perovskite precursor displays drastic degradation under ISOS-L1 (100 mW/cm2, 25 °C, maximum power point tracking) conditions. However, postdegradation analysis contradicts these results. Devices with PbI2/FAI ≤ 1.1 are stable under light, but intermittent current density-voltage characterizations indicate that device performance decreases during storage in the dark. Migration of iodide (I-) ions to the electron-transport layer (ETL) and iodine vacancies (VI-+) to the hole-transport layer (HTL) forms localized shunts in the absorber layer. Pinhole formation, surrounded by FA+-rich regions, explains the extent of damage in comparably aged films. In summary, this work emphasizes the importance of reporting stability under different stress conditions, coupled with postdegradation and dark recovery analyses of PSCs to better understand the complexities of perovskite instability under real-life conditions such as expected during outdoor operation.

Tomato Fruit Detection Using Modified Yolov5m Model with Convolutional Neural Networks.

The farming industry is facing the major challenge of intensive and inefficient harvesting labors. Thus, an efficient and automated fruit harvesting system is required. In this study, three object classification models based on Yolov5m integrated with BoTNet, ShuffleNet, and GhostNet convolutional neural networks (CNNs), respectively, are proposed for the automatic detection of tomato fruit. The various models were trained using 1508 normalized images containing three classes of cherry tomatoes, namely ripe, immature, and damaged. The detection accuracy for the three classes was found to be 94%, 95%, and 96%, respectively, for the modified Yolov5m + BoTNet model. The model thus appeared to provide a promising basis for the further development of automated harvesting systems for tomato fruit.

Classification of Tomato Fruit Using Yolov5 and Convolutional Neural Network Models.

Four deep learning frameworks consisting of Yolov5m and Yolov5m combined with ResNet50, ResNet-101, and EfficientNet-B0, respectively, are proposed for classifying tomato fruit on the vine into three categories: ripe, immature, and damaged. For a training dataset consisting of 4500 images and a training process with 200 epochs, a batch size of 128, and an image size of 224 × 224 pixels, the prediction accuracy for ripe and immature tomatoes is found to be 100% when combining Yolo5m with ResNet-101. Meanwhile, the prediction accuracy for damaged tomatoes is 94% when using Yolo5m with the Efficient-B0 model. The ResNet-50, EfficientNet-B0, Yolov5m, and ResNet-101 networks have testing accuracies of 98%, 98%, 97%, and 97%, respectively. Thus, all four frameworks have the potential for tomato fruit classification in automated tomato fruit harvesting applications in agriculture.

Transoral endoscopic thyroidectomy vestibular approach as a novel technique for pediatric populations: Results from a single surgeon.

Background: The transoral endoscopic thyroidectomy vestibular approach (TOETVA) is increasingly being adopted worldwide because of its many advantages. However, there are few reports on the effectiveness and safety of TOETVA in children. In this study, we report the results of the application of TOETVA on 27 pediatric patients in Vietnam. To the best of our knowledge, this is also the largest sample size of the TOETVA technique performed by a single surgeon on pediatric patients worldwide. Patients and methods: From June 2020 to February 2022, we performed TOETVA on 27 pediatric patients (≤ 18 years old). The outcomes of the procedure were retrospectively reviewed. Results: Our study was conducted on 27 pediatric patients, of whom 24 were female (88.9%). The mean age was 16.3 ± 2 (range 10-18). Fifteen patients had benign thyroid nodules with a mean nodule size of 31.6 ± 7.1 (range 20-50mm), and 12 patients had papillary thyroid carcinoma with a mean nodule size of 10.2 ± 5.6 (range 4-19mm). All 27 patients underwent successful TOETVA without any conversion to open surgery. The 15 patients with benign thyroid nodules had lobectomies with a mean operative time of 83.3 ± 10.5 (range 60-105 minutes). Among the 12 patients diagnosed with thyroid cancer, ten had a lobectomy, isthmusectomy, and central neck dissection, with a mean operative time of 89.8 ± 5.7 (range 80-100 minutes). The other two underwent total thyroidectomy with central lymph node dissection with a mean operative time of 132.5 minutes. The mean hospital stay was 4.7 ± 0.9 (range 3-7 days). No patient had permanent complications, such as hypocalcemia, recurrent laryngeal nerve injury, or mental nerve injury. The rates of temporary recurrent laryngeal nerve injury and mental nerve injury were 3.7% and 11.1% respectively. Conclusions: TOETVA may be a feasible and safe surgical method for children with thyroid disease. However, we recommend that only high-volume thyroid surgeons with experience in TOETVA should perform TOETVA on the pediatric population.

Prophylactic Central Neck Dissection to Improve Disease-Free Survival in Pediatric Papillary Thyroid Cancer.

Background: Pediatric PTC is a rare disease. Although, the prognosis is excellent and the mortality rate is low, the role of prophylactic central neck dissection is still the subject of debate. The aim was to evaluate both the role and safety of prophylactic central neck dissection (CND) in managing pediatric papillary thyroid cancer (PTC), especially in respect of disease-free survival (DFS). Patients and Methods: In this retrospective study, we collected 54 pediatric cN0 PTC patients (≤ 18 years of age) who were treated from January 2014 to January 2021 at a high-volume thyroid surgery center. Patients were divided into two groups based on the status of prophylactic CND. We analyzed the factors related to the clinicopathological features and recurrence of PTC in children. Results: Of the 54 cN0 patients, 35 underwent prophylactic CND and 19 patients did not undergo prophylactic CND. The two groups were similar in clinical and pathologic features, such as age, gender, tumor size, multifocal status, and follow-up time. The average DFS was 84.4 ± 2.7 months. Log-rank tests on Kaplan-Meier curves revealed that age, gender, tumor size, multifocality, and extrathyroid extension did not relate to DFS time. Furthermore, DFS time was not affected by the extent of thyroidectomy (p=0.07) or RAI treatment (p=0.21). Prophylactic CND was found to increase DFS time for pediatric patients with cN0 PTC (p = 0.003). There was no statistically significant difference in complications such as transient hypocalcemia (p=0.15) and transient recurrent laryngeal nerve injury (p=0.37) between the prophylactic CND group and the no-prophylactic CND group. Conclusion: Prophylactic CND was found to be associated with increased DFS and not with increased rates of complications after surgery.