RESUMO
Besides further improvement in the power conversion efficiency (PCE) of perovskite solar cells (PSC), their long-term stability must also be ensured. Additives such as organic cations with halide counter anions are considered promising candidates to address this challenge, conferring both higher performance and increased stability to perovskite-based devices. Here, a stabilizing additive (N,N-dimethylmethyleneiminium chloride, [Dmmim]Cl) is identified, and its effect on charge carrier mobility and lifetime under thermal stress in triple cation perovskite (Cs0.05 MA0.05 FA0.90 PbI3 ) thin films is investigated. To explore the fundamental mechanisms limiting charge carrier mobility, temperature-dependent microwave conductivity measurements are performed. Different mobility behaviors across two temperature regions are revealed, following the power law Tm , indicating two different dominant scattering mechanisms. The low-temperature region is assigned to charge carrier scattering with polar optical phonons, while a strong decrease in mobility at high temperatures is due to dynamic disorder. The results obtained rationalize the improved stability of the [Dmmim]Cl-doped films and devices compared to the undoped reference samples, by limiting temperature-activated mobile ions and retarding degradation of the perovskite film.
RESUMO
Thread carpal tunnel release (TCTR) has been reported to be safe and effective for the treatment of carpal tunnel syndrome. The aim of this study is to evaluate the modified TCTR for safety, efficacy, and postoperative recovery. Seventy-six extremities in 67 patients undergoing TCTR were analyzed pre- and postoperatively using clinical parameters and patient-reported outcome measures. Twenty-nine men and 38 women with a mean age of 59.9 ± 18.9 years underwent TCTR. The mean postoperative time to resume activities of daily living was 5.5 ± 5.5 days, analgesia was completed after 3.7 ± 4.6 days, and return to work was achieved after a mean of 32.6 ± 15.6 days for blue-collar workers and 4.6 ± 4.3 days for white-collar workers. The Boston Carpal Tunnel Questionnaire (BCTQ) and Disability of Arm, Shoulder, and Hand (DASH) scores were comparable with previous studies. Overall, two persistent compressions and one recurrence required open reoperation (3.9%). All three had been operated in the initial phase, and none required reoperation after an additional safety step was introduced. No other complications occurred. TCTR surgery appears to be a safe and reliable technique with almost no wound and scarring and a potentially faster recovery time than open techniques. Although our technical modifications may reduce the risk of incomplete release, TCTR requires both ultrasound and surgical skills and has a considerable learning curve.
RESUMO
Despite the remarkable progress in power conversion efficiency of perovskite solar cells, going from individual small-size devices into large-area modules while preserving their commercial competitiveness compared with other thin-film solar cells remains a challenge. Major obstacles include reduction of both the resistive losses and intrinsic defects in the electron transport layers and the reliable fabrication of high-quality large-area perovskite films. Here we report a facile solvothermal method to synthesize single-crystalline TiO2 rhombohedral nanoparticles with exposed (001) facets. Owing to their low lattice mismatch and high affinity with the perovskite absorber, their high electron mobility and their lower density of defects, single-crystalline TiO2 nanoparticle-based small-size devices achieve an efficiency of 24.05% and a fill factor of 84.7%. The devices maintain about 90% of their initial performance after continuous operation for 1,400 h. We have fabricated large-area modules and obtained a certified efficiency of 22.72% with an active area of nearly 24 cm2, which represents the highest-efficiency modules with the lowest loss in efficiency when scaling up.
