Highly Efficient and Stable Perovskite Solar Cells Based on Monolithically Grained CH3NH3PbI3 Film

The synthesis and growth of perovskite films with controlled crystallinity and microstructure for highly efficient and stable solar cells is a critical issue. In this work, thiourea is introduced into the CH₃NH₃PbI₃ precursor with two‐step sequential ethyl acetate (EA) interfacial processing. This is shown for the first time to grow compact microsized and monolithically grained perovskite films. X‐ray diffraction patterns and infrared spectroscopy are used to prove that thiourea significantly impacts the perovskite crystallinity and morphology by forming the intermediate phase MAI·PbI₂·S?C(NH₂)₂. Afterward, the residual thiourea which coursed charge recombination is completely extracted by the sequential EA processing. The product has improved light harvesting, suppressed defect state, and enhanced charge separation and transport. The sequentially EA processed perovskite solar cells offer an impressive 18.46% power conversion efficiency and excellent stability in ambient air. More importantly, the EA postprocessed perovskite solar cells also have excellent voltage response under ultraweak light (0.05% sun) with promising utility in photodetectors and photoelectric sensors.     

Toward Long‐Term Stable and Highly Efficient Perovskite Solar Cells via Effective Charge Transporting Materials

Perovskite solar cells (PSCs) have advanced quickly with their power conversion efficiency approaching the record of silicon solar cells. However, there is still a big challenge to obtain both high efficiency and long‐term stability for future commercialization of PSCs. The major instability issue is associated with the decomposition or phase transition of perovskite materials that are believed to be intrinsically unstable under outdoor working conditions. Herein, the authors review the approaches that marked important progress in developing new functional electron/hole transporting materials that enabled highly efficient and stable PSCs. The findings that accelerate charge diffusion and that suppress the irrevocable loss of ions diffusing out of perovskite materials and other diffusion processes are highlighted. In addition, derivative interface engineering methods to control the diffusion process of charges/ions/molecules are also reviewed. Finally, the authors propose key research issues in charge transporting materials and interface engineering with regard to the important diffusion processes that will be one of the keys to realize highly efficient and long‐term stable PSCs.     

不同激光照射方法对周围神经再生的影响

为研究不同半导体激光照射方法对周围神经损伤的影响,将96只家兔随机分为3周,6周,9周,12周4个观察期组,每个观察期组又随机分为不同照射方法的治疗组和对照组。建立动物模型后,各照射组在术后1d开始照射治疗,激光功率为10mw,每次照射10rain,每天一次,连续照射10d。照射治疗A组对准损伤神经吻合部位进行照射,照射治疗B组照射家兔L5、L6脊髓节段,照射治疗c组在对准吻合处进行照射同时还要照射L5、L6脊髓节段,对照组激光输出功率为零。实验结果表明低能量半导体激光照射能促进轴突再生,改善再生神经功能,以同时照射损伤周围神经部位和相应脊髓节段效果最为显著。