In recent years, graphene studies have increased rapidly. Graphene oxide, which is an intermediate product to form graphene, is insulating, and it should be thermally reduced to be electrically conductive. We herein describe an attempt to make use of the insulating properties of graphene oxide. The graphene oxide layers are deposited onto Si substrates, and a metal-insulator-semiconductor tunneling structure is formed and its optoelectronic properties are studied. The accumulation dark current and inversion photocurrent of the graphene oxide device are superior to the control device. The introduction of graphene oxide improves the rectifying characteristic of the diode and enhances its responsivity as a photodetector. At 2 V, the photo-to-dark current ratio of the graphene oxide device is 24, larger than the value of 15 measured in the control device.