Jingxiao Lu

Multiplied magnetoelectric effect in multi-faceted magnetoelectric composite

A four-faceted magnetoelectric (ME) composite consisting of one cuboid bonded Terfenol-D composite and four plates of Pb(Zr,Ti)O3 (PZT) was fabricated. The ME voltage coefficients were measured along the length direction of the composite when PZT plates were parallelly or serially connected. Results show that the ME voltage coefficient remains almost the same when increasing the number of PZT in parallel mode. By contrast, the ME voltage coefficient increases multiplicatively with the increasing of the number of PZT in serial mode. This multi-faceted structure scheme offers an effective approach to improving ME effect and downsizing the ME devices.

The simulation of physical mechanism for HTM-free perovskite organic lead iodide planar heterojunction solar cells

Recently, organo-metal halide perovskites have attracted much attention from the scientific community because of their successful application in the absorber layer of low-cost solar cells. For the further improvement of the performance of such cells, a thorough understanding of the influence of the material properties on the working mechanism of a device is very necessary and important. In this study, two-dimensional modeling of hole transport material free planar heterojunction solar cells was performed, in which electromagnetic simulation was directly linked to carrier transport calculations. An optimum absorber thickness of 200 nm was reproduced in the simulation at carrier diffusion length of 100 nm, in good agreement with previous experiments. This optimum thickness increased with the increase of diffusion length, and an efficiency of about 11% was obtained at 300 nm with a diffusion length of 300 nm. Finally, it was demonstrated that the relatively low efficiency of such solar cells was directly related to the low short-circuit photocurrent density (J SC) and the low open-circuit voltage (V OC) due to the insufficient absorption of the long-wavelength region and the nearly intrinsic doping concentration, respectively.