Right This is the peer reviewed version of the following article: Nakatsuka, S., Nakamoto, H., Nose, Y., Uda, T. and Shirai, Y. (2015), Bulk crystal growth and characterization of ZnSnP2 compound semiconductor by flux method. Phys. Status Solidi C, 12: 520‒523, which has been published in final form at http://dx.doi.org/10.1002/pssc.201400291. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.; The full-text file will be made open to the public on 30 March 2016 in accordance with publisher's 'Terms and Conditions for SelfArchiving'.; この論文は出版社版でありません。引用の際 には出版社版をご確認ご利用ください。This is not the published version. Please cite only the published version.

Time evolution of the chemical and structural properties of vacuum-ultraviolet (VUV) reduced graphene oxide (rGO) were studied by X-ray photoelectron spectroscopy and Kelvin-probe force microscopy to reveal the mechanism of VUV photoreduction, which can be ascribed to the local photochemical process on oxygen-containing functional groups. The difference in the efficiency between VUV and ultraviolet was demonstrated and the mechanism was discussed. The lateral electrical conductivity of VUV-produced rGO bilayer was measured by conductive atomic force microscopy, which was found to be higher than rGO monolayer due to the formation of new conductive paths between layers. The precision and resolution of VUV photo-reductive patterning was improved by collimating the VUV light. This new approach succeeded in fabricating highly-resolved 1 mm wide conductive rGO patterns on SiO2/Si substrate. (C) 2017 Elsevier Ltd. All rights reserved.

ZnSnP2 is a promising candidate for solar absorber materials from the viewpoint of high absorption and earth-abundant constitution elements. In this paper, we fabricated ZnSnP2 crystals by flux method based on the phase diagram of Sn-ZnP2 pseudo-binary system and investigated their properties for an application to photovoltaics. The crystal growth experiments with the cooling rate of 0.7 and 12 degrees C/h were carried out and we successfully obtained ZnSnP2 crystals with the diameter of 8mm and the thickness of a few mm by a slow cooling rate. The structure of grown crystals studied by X-ray diffraction was indicated to be chalcopyrite-type ZnSnP2. In addition, the decrease of the degree of order was observed with the increase of cooling rate. The lattice constants of a and c axes are 5.649 and 11.295 angstrom, respectively. The composition of grown crystals is a near stoichiometric ratio of ZnSnP2 by EDX analysis. The bandgaps of ZnSnP2 crystals obtained by cooling rate of 0.7 and 12 degrees C/h were estimated to be 1.61 and 1.48 eV, respectively, which is caused by the difference of the degree of order. The hall-resistivity measurement showed that ZnSnP2 crystals with a slow cooling rate has a p-type conduction. The resistivity, the hole concentration and the mobility are 10 similar to 70 Ocm, 6.10(16)similar to 2.10(17) cm(-3), and 1 similar to 3 cm(2)V(-1)s(-1). The obtained properties are suitable for an absorber of photovoltaics.