Superconducting nanowire single-photon detectors (SNSPDs) wherein ultrathin films are fabricated on Si substrates are greatly affected by lattice mismatch between the thin film and the substrate. A buffer layer can be used to reduce such lattice mismatch or optimize the strain in the film, thereby improving device performance. We prepared and optimized Nb₅N₆ as a buffer layer and found that it considerably improved the properties of NbN films on Si substrates. The zero-resistance critical temperature (T _C0) of a 3 nm thick NbN film with a 20 nm thick buffer layer was 10.3 K. SNSPDs with Nb₅N₆-buffered NbN films were fabricated and compared with normal devices; the fabricated devices had high hysteresis current and low timing jitter. Furthermore, we investigated the thermal diffusion process of the device based on the hysteresis current and hotspot relaxation time and found that Nb₅N₆ buffer layers enhance the thermal coupling between the superconducting film and substrates. The relaxation time of buffered SNSPD was 14.2 ps, which was shorter than that of nonbuffered SNSPD by 17.8 ps. These effects explain the performance improvement observed in the case of the buffered devices.

超导纳米线单光子探测器 (SNSPD)，其中在 Si 衬底上制造超薄膜，受薄膜和衬底之间晶格失配的影响很大。缓冲层可用于减少这种晶格失配或优化薄膜中的应变，从而提高器件性能。我们制备并优化了 Nb ₅ N ₆作为缓冲层，发现它显着改善了 Si 衬底上 NbN 薄膜的性能。具有 20 nm 厚缓冲层的 3 nm 厚 NbN 膜的零电阻临界温度 ( T _C0 ) 为 10.3 K。具有 Nb ₅ N _{6 的}SNSPDs- 制备缓冲 NbN 薄膜并与普通器件进行比较；制造的器件具有高滞后电流和低时序抖动。此外，我们基于滞后电流和热点弛豫时间研究了器件的热扩散过程，发现 Nb ₅ N ₆缓冲层增强了超导薄膜和衬底之间的热耦合。缓冲 SNSPD 的弛豫时间为 14.2 ps，比非缓冲 SNSPD 的弛豫时间短 17.8 ps。这些影响解释了在缓冲设备的情况下观察到的性能改进。