The electrical and photo-sensing properties of horizontally-oriented interconnected carbon nanotube networks (CNT-NWs) prepared by means of a microwave plasma chemical vapor deposition sandwich-growth process are investigated. The temperature-dependent dark and illuminated current-voltage and transfer characteristics of CNT-NW-assisted devices are measured. Results show that the current-voltage characteristics of the devices exhibit nonlinear behavior, and the current can be further modulated by a gate voltage, revealing p-type semiconducting behavior with a device mobility of ∼ 14.5 cm 2/V·s and an on-off current ratio of ∼ 103. Moreover, when the CNT-NW-assisted devices are irradiated with 1.25-25 μm infrared (IR) from 300 to 11 K, the photo currents increase approximately 1.1- to 2.7-fold compared to the dark currents at ± 2 V bias voltage. Such results demonstrate that the presented CNT-NWs have high potential for IR photo-sensor applications.