Naphthalene Diimide-Modified SnO2 Enabling Low-Temperature Processing for Efficient ITO-Free Flexible Perovskite Solar Cells.

A low-cost and indium-tin-oxide (ITO)-free electrode-based flexible perovskite solar cell (PSC) that can be fabricated by roll-to-roll processing shall be developed for successful commercialization. High processing temperatures present a challenge for the PSC fabrication on flexible substrates. The most efficient planar n-i-p PSC structures, which utilize a metal oxide as an electron transport layer (ETL), necessitate high annealing temperatures. In addition, the device performance deteriorates owing to the migration of halogen ions, which causes the oxidation of the metal electrodes. These drawbacks conflict with the development of highly efficient flexible PSCs fabricated on ITO-free transparent electrodes. Herein, an efficient ETL material that enables low-temperature processing is presented. Tin dioxide (SnO2) is modified by (sulfobetaine-N,N-dimethylamino)propyl naphthalene diimide (NDI-B) and used as an ETL. The NDI-B effectively reduces the interfacial nonradiative recombination between the ETL and perovskite and suppresses the ion migration by passivating oxygen-vacancy defects in SnO2 and strongly interacting with halogen ions, respectively. Based on the NDI-B-blended SnO2 ETL, a record PCE of 17.48% is achieved in the ITO-free flexible PSC fabricated at low temperature.

Effect of foot reflexology on an infant with sensorineural hearing loss: A case report.

BACKGROUND: Our study contributes to the further understanding of the mechanism of foot reflexology. Foot reflexology has been reported to affect hearing recovery, but no physiological evidence has been provided. This lack of evidence hampers the acceptance of the technique in clinical practice. CASE SUMMARY: A girl was taken to North Sichuan Medical University Affiliated Hospital for a hearing screen by her parents. Her parents reported that her hearing level was the same as when she was born. The girl was diagnosed with sensorineural hearing loss (SNHL) by a doctor in the otolaryngology department. After we introduced the foot reflexology project, the parents agreed to participate in the experiment. After 6 months of foot reflexology treatment, the hearing threshold of the girl recovered to a normal level, below 30 dB. CONCLUSION: Foot reflexology should be encouraged in clinical practice and for families of infants with SNHL.