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The overloaded energy cost has become the main concern of the now fast developing society, which make novel energy devices with high power density of critical importance to the sustainable development of human society. Herein, a dynamic Schottky diode based generator with ultrahigh power density of 1262.0 W m−2 for sliding Fe tip on rough p‐type silicon is reported. Intriguingly, the increased surface states after rough treatment lead to an extremely enhanced current density up to 2.7 × 105 A m−2, as the charged surface states can effectively accelerate the carriers through large atomic electric field, while the reflecting directions are regulated by the built‐in electric field of the Schottky barrier. This research provides an open avenue for utilizing the surface states in semiconductors in a subversive way, which can co‐utilize the atomic electric field and built‐in electric field to harvest energy from the mechanical movements, especially for achieving an ultrahigh current density power source. [ABSTRACT FROM AUTHOR]

Abstract: Y2O2S co-doped with Bi3+,Eu3+ phosphors were prepared and their luminescence properties under vacuum ultraviolet (VUV) excitation were investigated. Much stronger red emission for Y2O2S:Eu3+,Bi3+ were observed under 147nm excitation than that for Y2O2S:Eu3+. Investigation on photoluminescence and calculation of electronic structure of Y2O2S:Eu3+,Bi3+ revealed that the Bi3+ acts as a medium in energy transfer process and the great VUV luminescence enhancement of Y2O2S:Eu3+ by doping Bi3+ is due to effective energy transfer process: charge transfer (CT) transition of Y3+–O2− →Bi3+ →Eu3+. The Y2O2S:Eu3+,Bi3+ showed excellent optical properties when compared with the commercial (Y,Gd)BO3:Eu3+. Thus, the Y2O2S:Eu3+,Bi3+ would be a promising VUV-excited red phosphor. [Copyright &y& Elsevier]

Abstract: Undoped and RE ions doped SrB2Si2O8 were successfully synthesized. After the application of UV and VUV spectroscopy measurements, we made a novel discovery that the emission of SrB2Si2O8:Eu prepared in air can be switched between red and blue by the different excitations. The information is that quite a part of Eu3+ was spontaneously reduced to Eu2+ in air. The PL properties of Eu2+ in VUV and Eu3+, Ce3+ and Tb3+ in UV–VUV region in SrB2Si2O8 were evaluated for the first time. The excitation mechanisms of the O2−–Eu3+ CT, Ce3+ f–d and Tb3+ f–d transitions in UV region as well as the Eu3+ f–d, O2−–Ce3+ CT, O2−–Tb3+ CT transitions and the host lattice absorption in VUV region were established. In addition, first principles calculation within the LDA of the DFT was applied to calculate the electronic structure and linear optical properties of SrB2Si2O8 and the results were compared with the experimental data. [Copyright &y& Elsevier]

The overloaded energy cost has become the main concern of the now fast developing society, which make novel energy devices with high power density of critical importance to the sustainable development of human society. Herein, a dynamic Schottky diode based generator with ultrahigh power density of 1262.0 W m−2 for sliding Fe tip on rough p‐type silicon is reported. Intriguingly, the increased surface states after rough treatment lead to an extremely enhanced current density up to 2.7 × 105 A m−2, as the charged surface states can effectively accelerate the carriers through large atomic electric field, while the reflecting directions are regulated by the built‐in electric field of the Schottky barrier. This research provides an open avenue for utilizing the surface states in semiconductors in a subversive way, which can co‐utilize the atomic electric field and built‐in electric field to harvest energy from the mechanical movements, especially for achieving an ultrahigh current density power source. [ABSTRACT FROM AUTHOR]

Since the discovery of two dimensional (2D) materials, there has been a gold rush for van der Waals integrated 2D material heterostructure based optoelectronic devices. Van der Waals integration involves the physical assembly of the components of the device. In the present work, we extended van der Waals integration from 2D materials to three-dimensional (3D) materials, and herein we uniquely designed a van der Waals contacted light emitting diode based on MoO x staked ZnO/GaN heterostructure. The presence of the MoO x layer between n-type ZnO and p-type GaN leads to the confinement of electrons and an increase in the electron charge density at n-type ZnO. The n-type MoO x , a well-known hole injection layer, favors the availability of holes at the ZnO site, leading to the efficient recombination of electrons and holes at the ZnO site, which results in predominant high-intensity UV-EL emission around 380 nm in both forward and reverse bias.

The overloaded energy cost has become the main concern of the now fast developing society, which make novel energy devices with high power density of critical importance to the sustainable development of human society. Herein, a dynamic Schottky diode based generator with ultrahigh power density of 1262.0 W m -2 for sliding Fe tip on rough p-type silicon is reported. Intriguingly, the increased surface states after rough treatment lead to an extremely enhanced current density up to 2.7 × 10 5 A m -2 , as the charged surface states can effectively accelerate the carriers through large atomic electric field, while the reflecting directions are regulated by the built-in electric field of the Schottky barrier. This research provides an open avenue for utilizing the surface states in semiconductors in a subversive way, which can co-utilize the atomic electric field and built-in electric field to harvest energy from the mechanical movements, especially for achieving an ultrahigh current density power source., Competing Interests: The authors declare no conflict of interest., (© 2019 The Authors. Published by WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.)