A sharp response of infrared light detecting capability is observed in reduced graphene oxide based photodetector. The photoresponse increased with increasing solution concentration and annealing duration, at a low percolation. The photocurrent increases considerably before saturation and persists for a maximum time of 26 min. This Letter also reports on superiority of device performance with continuous annealing over annealing with an interval. A maximum photoresponsivity of 0.55 A/W and external quantum efficiency of 57% was achieved at low power light intensity (0.8 mW/cm(2)). This Letter presents an efficient graphene oxide thin film infrared photodetector processed via a modified synthesis protocol. (C) 2014 Elsevier B. V. All rights reserved.