The above optical characterization based on the measurements of transmission spectra and PL spectra reveal that the fabricated ZnO/ZnSe core/shell NRs have a photoresponse much broader than those of the constituting materials ZnO and ZnSe. The extending

of photoresponse makes the ZnO/ZnSe core/shell NRs promising as absorbent materials of solar radiation in solar devices. Conclusion In this work, we studied the optical properties of vertically aligned ZnO/ZnSe core/shell NRs after morphology and structure characterization. By pulsed laser deposition of ZnSe on the surfaces of hydrothermally grown ZnO NRs, type-II ZnO/ZnSe heterojunctions constructed of ZnO cores and ZnSe shells were fabricated. The ZnO core NRs grown vertically on the substrates are composed of nanocrystallites with wurtzite structure, while the ZnSe shells, also composed of nanocrystallites, are zinc blende in crystal structure. VS-4718 clinical trial The structures of both the ZnO cores and the ZnSe shells can be improved by post-fabrication annealing in N2. High-temperature deposition of ZnSe has also annealing effects on the structure of the ZnO cores. At room temperature, the ZnO NRs exhibit a good behavior on UV NBE RepSox cell line emission with a weak defect-related visible emission, whereas only a weak PL is observed from the ZnO/ZnSe core/shell NRs because of the suppression of the emission from ZnO cores by the ZnSe shells. The

ZnO/ZnSe core/shell NRs fabricated by depositing ZnSe at KU-57788 cell line elevated temperatures are superior to the samples fabricated by depositing ZnSe at room temperature both in structure and optical properties. Multi-band luminescence including

the UV NBE emission of ZnO and the blue NBE emission of ZnSe is observed from the samples fabricated by depositing ZnSe at 500°C on the hydrothermally grown ZnO NRs. In addition, the ZnO/ZnSe core/shell NRs fabricated with the deposition of ZnSe at 500°C show an extended photoresponse much broader than those of the constituting ZnO and ZnSe. Acknowledgements This Gemcitabine clinical trial work is supported by the National Basic Research Program of China (Contract No. 2012CB934303) and the National Natural Science Foundation of China (Contract No. 11275051). Acknowledgment is also given to the Doctoral Fund of Ministry of Education of China (Contract No. 20110071110020). References 1. Pearton SJ, Norton DP, Ip K, Heo YW, Steiner T: Recent progress in processing and properties of ZnO. Superlattice Microst 2003, 34:3–32.CrossRef 2. Cho S, Jang J-W, Kim J, Lee JS, Choi W, Lee K-H: Three-dimensional type II ZnO/ZnSe heterostructures and their visible light photocatalytic activities. Langmuir 2011, 27:0243–10250. 3. Ramnathan K, Contreas MA, Perkins CL, Asher S, Hasoon FS, Keane J, Young D, Romero M, Metzger W, Noufi R, Ward J, Duda A: Properties of 19.2% efficiency ZnO/CdS/CuInGaSe 2 thin-film solar cells. Prog Photovolt 2003, 11:225–230.CrossRef 4.