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WS2 layered material offers a great potential for the development of next generation laser photonic devices due to its strong layer absorption compared with graphene. The passively Q-switched Nd:YVO4 laser operating at 1064 nm was first demonstrated by using layered tungsten disulfide WS2 saturable absorber SA, which was fabricated by using radio frequency magnetron sputtering method. The fabrication method is scalable and capable of producing large size sample with high uniformity. Besides, the thickness of produced sample can be well-controlled by adjusting sputtering time. A stable Q-switched laser operation is achieved by using this home made few layers WS2-SA within a diode-pumped Nd:YVO4 laser cavity. The maximum average output power obtained is 19.6 mW corresponding to a repetition rate of 135 kHz, a pulse duration of 2.3 μs and single pulse energy of 145 nJ. This result proves the promising Q-switching performance of the fabricated WS2-SA.

Here, we report a new metallization scheme for achieving excellent ohmic contact to p-type II-VI nanostructures at room temperature. Bilayer electrodes consisting of Cu (4 nm)/Au (50 nm) provided a specific contact resistivity as low as 5.6 × 10-7 Ω cm2 with p-ZnS nanoribbons (NRs). Interface analysis via depth profiling X-ray photoemission spectroscopy, Auger electron spectroscopy, and high-resolution transmission electron microscopy revealed the formation of a highly conductive Cu2S interfacial layer, which could serve as the buffer layer and thus promote the hole transport from NR to electrode. High-performance Ti/p-ZnS NR Schottky barrier diodes were then fabricated based on the Cu/Au ohmic contact.