Suppressed Voltage Deficit and Degradation of Perovskite Solar Cells by Regulating the Mineralization of Lead Iodide.

Both the uncoordinated Pb2+ and excess PbI2 in perovskite film will create defects and perturb carrier collection, thus leading to the open-circuit voltage (VOC ) loss and inducing rapid performance degradation of perovskite solar cells (PSCs). Herein, an additive of 3-aminothiophene-2-carboxamide (3-AzTca) that contains amide and amino and features a large molecular size is introduced to improve the quality of perovskite film. The interplay of size effect and adequate bonding strength between 3-AzTca and uncoordinated Pb2+ regulates the mineralization of PbI2 and generates low-dimensional PbI2 phase, thereby boosting the crystallization of perovskite. The decreased defect states result in suppressed nonradiative recombination and reduced VOC loss. The power conversion efficiency (PCE) of modified PSC is improved to 22.79% with a high VOC of 1.22 V. Moreover, the decomposition of PbI2 and perovskite films is also retarded, yielding enhanced device stability. This study provides an effective method to minimize the concentration of uncoordinated Pb2+ and improve the PCE and stability of PSCs.

Recent advances in interface engineering of all-inorganic perovskite solar cells.

All-inorganic perovskite solar cells (PSCs) have become one of the most attractive research fields in recent years due to their excellent thermal stability and light stability as compared with their organic-inorganic hybrid counterparts. However, there is still a long way to go for their commercial application due to their low efficiency and poor stability under humidity conditions. Herein, an overview of the recent progress of all-inorganic PSCs based on interface engineering is provided. The main roles of interface engineering, adjusting energy-level alignment, enhancing charge transport capacity, passivating interface defects, modulating morphology of perovskite films, stabilizing perovskite phase, broadening spectral absorption, eliminating electrical hysteresis and enhancing operational stability, are summarized with examples, which paves the way for highly efficient and stable all-inorganic PSCs. Some of the latest progress in incorporating dopants to charge transport materials and modifying interface properties in all-inorganic PSCs are also covered.

Hierarchically Manipulated Charge Recombination for Mitigating Energy Loss in CsPbI2Br Solar Cells.

All-inorganic perovskite cesium lead iodide/bromide (CsPbI2Br) is considered as a robust absorber for perovskite solar cells (PSCs) because of its excellent thermal stability that guarantees its long-term operation stability. Efficient CsPbI2Br PSCs are available when obtaining low energy loss, which needs efficient charge generation, less charge recombination, and balanced charge extraction. However, numerous traps in perovskites hinder the photon-electron conversion process. Herein, hierarchical manipulation of charge recombination is proposed for CsPbI2Br PSCs featuring low energy loss. Nonselective trap reduction and selective halogen vacancy passivation are performed using 2,2'-(ethylenedioxy)diethylamine and phenylbutylammonium iodide for the bottom and top contacts, respectively. Because of all-around suppressed charge recombination, balanced charge extraction and suppressed hysteresis are realized. The champion PSC achieves an open-circuit voltage of 1.30 eV, a fill factor of 80.2%, and a power conversion efficiency of 16.6% that is 28.6% higher than that of the reference device. Moreover, the thermostability of PSCs is simultaneously enhanced because of the limited defect-assisted degradation.

[Effect of intensive insulin treatment on cardiac myocytes of severely scalded rats].

OBJECTIVE: To study the protective effect of intensive insulin treatment on cardiac myocytes of severely scalded rats. METHODS: Eighteen model Sprague-Dawley (SD) rats were subjected to 30% total body surface area (TBSA) full thickness injury, and they were divided into three groups with 6 rats in each group. The right jugular vein was cannulated for fluid resuscitation and administration of drugs. The rats in burn group were injected with normal saline, the intensive insulin group with injection of insulin to maintain plasma glucose content in normal range, and the sham burn group received physiologic dose of saline without burn injury. Plasma glucose was monitored after burn injury. Rats were sacrificed at 6 hours postburn to examine plasma myocardial enzymes spectrum as well as histological and ultrastructure changes in cardiac tissue. The expression of p-Akt was detected by western blotting. RESULTS: Plasma glucose level was significantly elevated in burn group within postburn 6 hours as compared with the sham burn group, and lowered in intensive insulin group (4.5 approximately 5.2 mmol/L vs. 7.6 approximately 8.4 mmol/L, P<0.05 or P<0.01). And the intensive insulin therapy could effectively inhibit the release of cardiac enzymes [lactate dehydrogenase (LDH): (2 369.3+/- 178.9) U/L vs. (2 684.1+/-335.0) U/L, P<0.05; alpha-hydroxybutyrate dehydrogenase (alpha-HBD): (576.7+/-219.2) U/L vs. (1 002.0+/-347.1) U/L, P<0.01; creatine kinase (CK): (1 041.9+/-623.2) U/L vs. (2 447.1+/-1 183.7) U/L, P<0.01]. The expression of p-Akt was significantly strengthened in the intensive insulin group (1.18+/-0.43 vs. 0.24+/-0.11, P<0.01). Light microscopic and electron microscopic examinations showed that intensive insulin therapy could alleviate the injury to myocardial cells and structural changes. CONCLUSION: Intensive insulin treatment possesses protective effect on cardiomyocytes after a severe burn, and it is related to its up-regulation of phosphorylation level of Akt in cardiomyocyte, thus inhibiting the damage to myocytes.