RESUMEN
With the development of superconducting nanowire single photon detectors, increasing numbers of important applications are being explored, covering not only low-energy optical photon detection but also high-energy photon and particle detection. In this work, 100-nm-thick TaN superconducting microwire single photon detectors (SMSPDs) with large active areas were prepared for X-ray detection, and their response characteristics to X-rays were studied. The results showed that our TaN SMSPDs were able to detect X-rays at a wide range of bias currents and working temperatures. The detectors could distinguish different energy X-rays under suitable working conditions, and the energy resolving power was strongly related to the bias current.
RESUMEN
Monolayer transition metal dichalcogenides (TMDCs) with high crystalline quality are important channel materials for next-generation electronics. Researches on TMDCs have been accelerated by the development of chemical vapor deposition (CVD). However, antiparallel domains and twin grain boundaries (GBs) usually form in CVD synthesis due to the special threefold symmetry of TMDCs lattices. The existence of GBs severely reduces the electrical and photoelectrical properties of TMDCs, thus restricting their practical applications. Herein, the epitaxial growth of single crystal MoS2 (SC-MoS2 ) monolayer is reported on Au (111) film across a two-inch c-plane sapphire wafer by CVD. The MoS2 domains obtained on Au (111) film exhibit unidirectional alignment with zigzag edges parallel to the <110> direction of Au (111). Experimental results indicated that the unidirectional growth of MoS2 domains on Au (111) is a temperature-guided epitaxial growth mode. The high growth temperature provides enough energy for the rotation of the MoS2 seeds to find the most favorable orientation on Au (111) to achieve a unidirectional ratio of over 99%. Moreover, the unidirectional MoS2 domains seamlessly stitched into single crystal monolayer without GBs formation. The progress achieved in this work will promote the practical applications of TMDCs in microelectronics.
