The UME Kibble balance project was initiated at the second half of 2014. During this period we have studied the theoretical aspects of Kibble balances in which an oscillating magnet generates AC Faraday's voltage in a stationary coil and constructed a trial version to implement this idea. The remarkable feature of this approach is that it can establish the link between the Planck constant and a macroscopic mass by one single experiment in the most natural way. Weak dependences on variations of environmental and experimental conditions, small sizes and other useful features offered by this novel approach reduce the complexity of the experimental setup. This paper describes the principles of oscillating magnet Kibble balance and gives details of the preliminary Planck constant measurements. The value of the Planck constant determined with our apparatus is with a relative standard uncertainty of 6 ppm.

This contribution demonstrates the effects of mole ratio, concentration of perovskite components and fullerene derivatives used as electron transport layer (ETL) on the stability and performances of inverted perovskite solar cells (PSCs). C60, C70, PC61BM and PC71BM are selected as ETL materials. Methylammonium iodide (MAI):Lead (II) iodide (PbI 2 ):Lead(II) chloride (PbCl 2 ) are used to form MAPb 2 I 2 Cl which is a mixed halogen perovskite structure. The fabricated perovskite device containing PCBM with optimized concentration and mole ratio gives high power conversion efficiency (PCE) of 9.07% with an open-circuit voltage (Voc) of 0.91 V, short circuit current density of 14.1 mA/cm 2 , and fill factor of 0.71. The lifetime characteristics and the stability are found significantly dependent on the fullerene type. The devices containing PC61BM and PC71BM are able to maintain 50% and 30% of its initial performances, respectively, even after 1100 hours. Overall, the obtained results represent an important step understanding the impacts on the p-i-n type perovskite lifetimes.

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