Automotive friction materials reinforced by home-made poly (p-phenylene benzobisoxazole) (PBO) pulp (fibrillated organic fibers) were prepared through compression molding. The friction and wear behaviors of the obtained composite materials were evaluated using a constant rotating speed type friction tester. The PBO pulp content and the testing loads showed clear influence on the tribological properties of the composites. Friction stability, wear rate, and morphology of sliding surfaces were carefully examined to investigate the effect of the pulp ingredient in the friction materials. Scanning electron microscopy was employed to study the morphology of the surface and wear particles. The significant wear reduction was achieved when the mass fraction of PBO pulp was 3%. Wear rates of the composites with 3% PBO pulp were measured over a load range from 0.3 to 1 MPa at different temperatures. The results pointed to two facts: (1) the wear rate of the friction material increased linearly with load at low temperature (below 200 C); (2) wear status varied with the testing loads at high temperature (above 250 C).
Perovskite solar cells (PSCs) have recently become a hot topic in photovoltaics due to their high power conversion efficiency (PCE) and low‐cost processing. As a key component of PSCs, electron transport layers (ETLs) that play a vital role in efficient PSCs generally require high charge extraction ability, mobility, and easy fabrication. Herein, a simple route to obtain dispersion of tin oxide nanocrystals (SnO2 NCs) with uniform diameters and high stability as efficient ETLs for CsPbI2Br solar cells is demonstrated. The champion device achieves a remarkable PCE of 16.22% with an open‐circuit voltage of 1.30 V. This work offers a facile and effective way to fabricate high‐performance ETL nanocrystals in PSCs.
Herein, the scalable chemical bath deposited NiOx‐NiSO4 heterostructured films are reported as the efficient hole transport layers (HTLs) in perovskite solar cells. The NiOx‐NiSO4 films show excellent hole extraction ability and reduce interfacial charge recombination in solar cell devices. By using NiOx‐NiSO4 HTLs, a high power conversion efficiency of 20.55% is obtained, which is about 12.23% greater than that of the pure NiOx transport layer. This study provides a simple solution‐processing route toward the large‐area production and fabrication of full inorganic transport layers for perovskite photovoltaics.
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