Hydrogen-peroxide-modified egg albumen for transparent and flexible resistive switching memory.

Egg albumen is modified by hydrogen peroxide with concentrations of 5%, 10%, 15% and 30% at room temperature. Compared with devices without modification, a memory cell of Ag/10% H2O2-egg albumen/indium tin oxide exhibits obviously enhanced resistive switching memory behavior with a resistance ratio of 104, self-healing switching endurance for 900 cycles and a prolonged retention time for a 104 s @ 200 mV reading voltage after being bent 103 times. The breakage of massive protein chains occurs followed by the recombination of new protein chain networks due to the oxidation of amidogen and the synthesis of disulfide during the hydrogen peroxide modifying egg albumen. Ions such as Fe3+, Na+, K+, which are surrounded by protein chains, are exposed to the outside of protein chains to generate a series of traps during the egg albumen degeneration process. According to the fitting results of the double logarithm I-V curves and the current-sensing atomic force microscopy (CS-AFM) images of the ON and OFF states, the charge transfer from one trap center to its neighboring trap center is responsible for the resistive switching memory phenomena. The results of our work indicate that hydrogen- peroxide-modified egg albumen could open up a new avenue of biomaterial application in nanoelectronic systems.

Boosting Performance of Inverted Perovskite Solar Cells by Diluting Hole Transport Layer.

In our study, by developing the diluted PEDOT:PSS (D-PEDOT:PSS) to replace PEDOT:PSS stock solution as hole transport layer (HTL) materials for fabricating the inverted perovskite solar cells (PSCs), the performance of developed device with ITO/D-PEDOT:PSS/MAPbI3-xClx/C60/BCP/Ag structure is enhanced distinctly. Experimental results reveal that when the dilution ratio is 10:1, the optimal power conversion efficiency (PCE) of the D-PEDOT:PSS device can reach up to 17.85% with an increase of 11.28% compared to the undiluted PEDOT:PSS device. A series of investigations have confirmed that the efficiency improvement is mainly attributed to the two aspects: on one hand, the transmittance and conductivity of D-PEDOT:PSS HTL are improved, and the density of defect states at the interface is reduced after dilution, promoting the separation and transmission of charges, thus the short-circuit current (JSC) is significantly increased; on the other hand, the work function of D-PEDOT:PSS becomes more consistent with perovskite layer, and the voltage loss is reduced, so that the higher open circuit voltage (VOC) is obtained. Our research has indicated that diluting HTL develops a simpler, more efficient and cost-effective method to further improve performance for inverted PSCs.