Photon-triggered electronic circuits have been a long-standing goal of photonics. Recent demonstrations include either all-optical transistors in which photons control other photons^1,2 or phototransistors with the gate response tuned or enhanced by photons^3,4,5. However, only a few studies report on devices in which electronic currents are optically switched and amplified without an electrical gate. Here we show photon-triggered nanowire (NW) transistors, photon-triggered NW logic gates and a single NW photodetection system. NWs are synthesized with long crystalline silicon (CSi) segments connected by short porous silicon (PSi) segments. In a fabricated device, the electrical contacts on both ends of the NW are connected to a single PSi segment in the middle. Exposing the PSi segment to light triggers a current in the NW with a high on/off ratio of >8 × 10⁶. A device that contains two PSi segments along the NW can be triggered using two independent optical input signals. Using localized pump lasers, we demonstrate photon-triggered logic gates including AND, OR and NAND gates. A photon-triggered NW transistor of diameter 25 nm with a single 100 nm PSi segment requires less than 300 pW of power. Furthermore, we take advantage of the high photosensitivity and fabricate a submicrometre-resolution photodetection system. Photon-triggered transistors offer a new venue towards multifunctional device applications such as programmable logic elements and ultrasensitive photodetectors.

光子触发的电子电路一直是光子学的长期目标。最近的演示包括光子控制其他光子^1,2的全光晶体管，或者通过光子^3、4、5调整或增强栅极响应的光电晶体管。。但是，只有很少的研究报道了在没有电门的情况下对电流进行光开关和放大的设备。在这里，我们展示了光子触发的纳米线（NW）晶体管，光子触发的NW逻辑门和单个NW光电检测系统。NW合成时，长晶硅（CSi）段由短孔硅（PSi）段连接。在制造的设备中，NW两端的电触点连接到中间的单个PSi段。将PSi段暴露在光下会触发NW中的电流，其开/关比高，> 8×10 ⁶。可以使用两个独立的光输入信号来触发沿NW包含两个PSi段的设备。使用局部泵浦激光器，我们演示了光子触发的逻辑门，包括AND，OR和NAND门。具有单个100 nm PSi段的直径25 nm的光子触发NW晶体管需要不到300 pW的功率。此外，我们利用了高光敏性，并制造了亚微米分辨率的光电检测系统。光子触发的晶体管为多功能设备的应用提供了新的场所，例如可编程逻辑元件和超灵敏光电探测器。