Partially Passivated Micro-pyramidal Silicon/ PEDOT:PSS Hybrid Solar Cells with high efficiency

Organic/inorganic hybrid solar cells can be attractive owing to the synergetic advantages of the high carrier mobility and efficiency from inorganic semiconductors and the simple process and low cost from organic semiconductors. Especially in case of Si/PEDOT:PSS hybrid solar cells, PEDOT:PSS acts as a hole-transport layer with high transparency and conductivity and enhances the efficiency of the solar cell. However, when PEDOT:PSS is applied to the micro-pyramidal Si surface to improve the light absorption, the conformal coating becomes very challenging due to the networking of long polymer chains. Namely, PEDOT:PSS tends to cover only the tip areas of micro pyramids instead of whole Si surfaces including deep valleys of Si micro pyramids, which causes the degradation of the hybrid solar cells because the uncovered Si surface acts as surface recombination centers as well as they are not contributing the separation of photo-excited electron-hole pairs. In this work, we suggest a novel local SiN passivation technique around the valleys of Si micro pyramids. The SiN passivation layer was synthesized by plasma-enhanced chemical vapor deposition. For the local passivation, we spin-coated photoresist (PR) on a micro-pyramidal SiN/Si surface, followed by two-step soft and hard baking at 85 ??C and 110 ??C, respectively. During the soft baking, PR flows towards the valleys of micro pyramids resulting in non-uniform PR coating thickness between the tip and valley areas. Because of the non-uniform PR thickness, we could obtain a partially-passivated Si surface after a chemical etching of the SiN layer using a buffered-oxide etchant (BOE). The Si/PEDOT:PSS hybrid solar cells are fabricated by a spin-coating of PEDOT:PSS on a partially-passivated micro-pyramidal Si surface, followed by a annealing at 130 ??C. The partially-passivated hybrid solar cells were demonstrated to have an enhanced power conversion efficiency, compared with the sample without the partial-passivation layer. This is due to the enhancement of minority carrier lifetime or lower surface recombination velocity as well as the anti-reflection effect of the remaining SiNx layer around the valley area of Si micro pyramids

Perioperative cutaneous complications in an elderly patient due to inappropriate use of a forced-air warming device and underbody blanket: a case report

Forced-air warming is commonly utilized to prevent perioperative hypothermia. Underbody warming blankets are often employed to secure a larger area for patient warming. While forced-air warming systems are generally regarded as safe, improper usage poses a risk of cutaneous complications. Additionally, the influence of underbody blankets on cutaneous complications remains uncertain. We present a case of cutaneous complications resulting from the improper utilization of a forced-air warming device and an underbody blanket. A 79-year-old man presented to the hospital for robotic proctectomy under general anesthesia. The surgery lasted for 7 hours, and the forced-air warming device with underbody blanket operated continuously for 5 hours intraoperatively. The surgery was completed without any incidents. However, first-degree burns on the patient’s back, along with superficial decubitus ulcers on his right scapula, were observed after surgery. To prevent cutaneous complications, clinicians must adhere to the manufacturer's guidelines when utilizing a forced-air warming system. Compared to overbody blankets, underbody blankets have limitations in monitoring cutaneous responses. Ensuring patient safety requires selecting an appropriate blanket for scheduled operations

Additional effect of magnesium sulfate and vitamin C in laparoscopic gynecologic surgery for postoperative pain management: a double-blind randomized controlled trial

Background This clinical trial was conducted to determine whether combined use of magnesium sulfate and vitamin C more significantly reduced postoperative fentanyl consumption and pain than magnesium sulfate or vitamin C alone. Methods The prospective, double-blinded, randomized controlled study enrolled 132 patients scheduled for laparoscopic gynecologic surgery. The patients were randomly allocated to one of the four groups (n = 33 for each group; Group M [magnesium sulfate 40 mg/kg], Group V [vitamin C 50 mg/kg], Group MV [magnesium sulfate 40 mg/kg and vitamin C 50 mg/kg] and Group C [isotonic saline 40 ml]). Cumulative postoperative fentanyl consumption (primary endpoint measure), postoperative pain score by numeric rating scale, and postoperative nausea and vomiting were recorded at 1, 6, 24, and 48 h after discharge from the postanesthesia care unit. Results Cumulative postoperative fentanyl consumption was significantly less in Groups M, V, and MV than in Group C at all time points. Group MV showed significantly less cumulative postoperative fentanyl consumption than Group M at postoperative 24 h (mean ± standard deviation, 156.6 ± 67.5 vs. 235.6 ± 94.6 µg, P = 0.001), as well as significantly less consumption than Groups M and V at postoperative 48 h (190.8 ± 74.6 vs. 301.0 ± 114.8 or 284.1 ± 128.6 µg, P < 0.001, P = 0.003, respectively). Conclusions Combined use of magnesium sulfate and vitamin C provides an additional benefit in postoperative pain management after laparoscopic gynecologic surgery in comparison to single administration of magnesium sulfate or vitamin C