Butane (C

4

H

10

) is a common flammable gas

and leakage at low and medium concentrations may cause explosions or poisoning

so highly sensitive and low-power detection is required. Conventional metal oxide semiconductor sensors rely on high-temperature excitation

and thus have the disadvantages of high power consumption and poor stability.Stannic oxide (SnO

2

)/zinc oxide (ZnO) heterojunction composite thin films are deposited by radio-frequency magnetron sputtering and integrat

ed with a 275nm ultraviolet (UV) laser to realize a room-temperature photoexcited butane sensor. Under UV irradiation at 340μW·cm

-2

the sensor detects butane in the range of 100×10

-6

-1000×10

-6

achieving response and recovery times of 24

69s

respectively

at 100×10

-6

.Compared to ethanol and ethylene

the sensor response to butane is five and nine times greater

respectively

demonstrating excellent selectivity. In the 30-day stability test

the response fluctuation of the sensor is only 0.5%

which verifies its good stability. This sensor has high sensitivity

rapid response

and long-term stability.It is suitable for real-time monitoring and early warning of low and medium concentration butane leakage at room temperature

and offers promising prospects for portable gas-detection applications.